I've had my Recalbox running on a rPi3+ for a few days. I like it so much, I'm building one for my brother and step-son. I'm willing to bet someone else has already noted this, but I could not find it via a Google Search and it was incredibly frustrating. As such, I'm hoping that this helps someone else out in the future. I also did a search on the forum before posting, maybe I'm thinking too hard and that's why I didn't find it.

I wanted to burn through Doom one more time now that I got my Recalbox up and running, but I didn't want to take the time to "Get Gud" like I did in 1996. I'm thinking this is like a great movie and you just want to fast forward through the boring set-up and find the most entertaining parts since you already know the backstory.

So I wanted to get some cheat codes working in PrBoom but for the life of me, could not get them to "stick" (and it didn't help that the files I found online are crap). As soon as I exit RetroArch, they were gone. I could not download them via online updater.
I even tried creating a them in RA and "Save Cheat File As" through the menu, but I don't know where the file goes, if it's saved at all. "find / -name FILENAME_I_JUST_CREATED.cht - print" yields no results.

Here's how I did it.

Log into your Recalbox via SSH. Each line is typed individually.

mount -o remount, rw /
cd /recalbox/share_init/cheats/cht/
mkdir Doom
cp DOS/DOOM.cht Doom/Doom.cht

First line remounts the partition as a read-write, the system won't let you make changes otherwise.
second line changes the directory to the actual cheat file location. I'm pretty sure "custom" that you find in the load cheat file menu is a symlink of some sort or hard coded to /recalbox/share/cheats/
third line creates a "Doom" directory which is case sensitive.
fourth line copies the already existing DOS Doom cheat file to the new directory with the case sensitive file name.

I hope this helps someone out because there's plenty of "Doom.cht" files online that are filled with hex codes that don't work. I'm willing to bet most people simply give up.

Now I know. I'll just make sure I add a copy of the global config to each .pc directory to simplify things.

Thanks.

I once again can not use Hotkey + B. Or any Hotkey + (except start).
Am I the only one experiencing this? Strange that it would reoccur a few days later, not immediately, not never. I do not believe I've made any configuration changes in the last 48 hours.

I gave up, restored from a fresh Rpi image.
Put all the setings back.
Everything is working again. No idea why it would suddenly revert.
This isn't a good solution, but it is a solution.
I also noticed that I had 240 test tools the popped up at the same time as the WiFi forgetting it's settings.
Strangely, I now have one PS4 controller that won't go into paring mode. It must be my magnetic personality.

@Smacaroni I was just able to confirm that yes, something automatically replaced my es_input.cfg file as I had a es_input.bak file created on or about October 18th. It would have lived in /recalbox/share/system/.emulationstation/ strangely, I still had a copy open in Notepad on my PC.
It has an element

<inputConfig type="joystick" deviceName="SHANWAN PS3 GamePad" deviceGUID="030000004c0500006802000010810000" deviceNbAxes="6" deviceNbHats="0" deviceNbButtons="17">

The file is missing and the es_input.cfg has no such element.

I don't mind this controller "going away", I probably won't use the knock-off PS3 controllers I have on this box. I just wanted to make note of the symptom.

My apologies for spamming my own thread, I guess I don't have enough reputation points to edit one of my posts.

@Smacaroni Oh, one more thing, 8.1.1 is the version. Rpi 4 8GB

I had built a Pi 3 RecalBox years ago, it was great. The Rpi board died, so I built another Pi 4 RecalBox, fresh install after reformatting the SD card (same ROMs copied to HDD on my PC.) New PS4 controllers (one genuine Sony, one knock-off)
It has not been so great of an experience. Wacky things seem to keep happening that I'm going forego listing to avoid muddying the conversation.

The latest problem started two days ago. I noticed that it was not connecting to WiFi. The SSID was gone?? So I re-entered the WiFi credentials, watched a bunch of TV via Kodi, went to bed.
Since then, I've noticed the following settings are not where I set them a week or so ago:
System time on menu
All controllers that I have not used in the last two days are gone.
Kodi X to start is now off, but I know I turned it on.
Overclocking set to none when I set it to 1600 for playable N64 games.
Keyboard mapping "1" to X button (to launch Kodi from the IR/Firestick/Keyboard remote). In fact, the es_inputs.cfg looks like the fresh install file, but I can't confirm for certain because in an attempt to fix the problem, I reconfigured both PS4 controllers which changed the file time stamp.
Hide "adult" games is off again.
I'm sure there are others.

Here's the one that I can't seem to solve, the "Hotkey + B" and other Hotkey + functions in RetroArch do not work except "Hotkey + Start" to exit the game.

The Google, she does nothing. It shows me many results for RetroPie and while I've tried to find the same config files in RecalBox, some do not exist and many are set the way that is recommended by those forums. Changing the ones that do not match have had no effect. So I restored them to the original state, having made copies of the original before monkeying with them.

I'm at a loss.
Anyone have any idea how I can restore HotKey + ? to work again?

Now I know. I'll just make sure I add a copy of the global config to each .pc directory to simplify things.

Thanks.

That will modify the global configuration unless you've created a local configuration. I was able to create a "pretty good" global config, but I need to make a few local configs for games that have different elements, like one uses space bar to shoot, another uses the CTRL key(s). My options are either to use a local file or to modify the key map each time I play a different game.
The key mapping took a bit of time to figure out, but that's not where the problem is.

The DOSbox docs say "settings that are left out are taken from the global file", but on RecalBox DOSbox, if the setting doesn't exist, it's either not being set or it's being pulled from an entirely different config file, but only when a local dosbox.cfg file is used.

also add a line "pause" to the end of your dosbox.bat this will allow you to see the error that's causing the program to die.

I'm a bit confused, according to the docs:
"dosbox.conf is a configuration file that DOSBox can use globally and/or locally per game (and settings that are left out are taken from the global file)"
https://www.dosbox.com/wiki/Dosbox.conf

But I created a dosbox.cfg, added one variable "mapperfile=mapper-0.74.map" in the local directory and I now have a screeen that is about 1/8th the actual screensize.
When I copy the entire ~/share/system/configs/dosbox.conf to ./dosbox.cfg, it works properly (and uses the local mapperfile.

Need some clarification since this behavior appears to be contradictory. Or did I miss something in the recalbox specific documentation?

Make sure you're using "SSH" and port 22. Putty default connections are for COM port connections.
Have you tried simply using "recalbox" instead of an IP?

Last, can you try either an alternate WiFi router such as your cell phone? Turn on moblie hot spot, connect your PC to your hotspot (might want to try some simple network tests to confirm it's working) then connect your RB to your phone?
Alternatively, you can use a RJ45 ethernet cross-over cable, but that's going to involve a lot more work using DOS commands like ARP.
Either of these will eliminate network rules that may be blocking the connection.