Recalbox 9.2.2 show wrong resolution using (hdmi_mode=87)

[porronca]

Board model: Raspberry Pi 3b
Recalbox version (build): 9.2.2 - Pulsar
Hardware:

• Sandisk 256GB SD card
• 5v 3a power supply
• Retroflag Megapi case
• Sony Wega CRT-TV (KV-29FS110) over component through this transcoder

I'll try to keep it brief:
I had a perfectly running system with a VGA666 board and a VGA to YPbPr transcoder.
Then, I decided to buy a Retroflag MegaPi case to make everything look nicer.
Unfortunately, it's not possible to use the VGA666 with this Retroflag case.

To solve this, I bought an HDMI to YPbPr transcoder that doesn't upscale the image at all the resolution and frequency that go in are the same as what comes out.
I followed the tutorial from Recalbox Wiki.

This setup worked fine on Recalbox 7.2.2.

• Emulation station in 480i
• Games in 240p

However, after Recalbox 9.2.2 fresh install, it seems recalbox.conf doesn't accept the global.videomode=DMT 87 HDMI command for the (1920x240 @ 60Hz) resolution (hdmi_cvt=1920 240 60 1 1 0 0) specified in recalbox-user-config.txt.
Instead, the system displays at (1280x720 @ 60Hz) - verified on a modern LCD TV -.
During boot, my monitor shows 480i, then switches to 1280x720 just before launching Emulation Station.

My goal is to archieve the same results as i got in Recalbox 7.2.2

Here are my recalbox-user-config.txt settings:

# Change to your needs
hdmi_cvt=1920 240 60 1 1 0 0
hdmi_pixel_encoding=2

# uncomment if you get no picture on HDMI for a default "safe" mode
#hdmi_safe=1

disable_overscan=0
overscan_scale=1

# uncomment to adjust overscan
overscan_left=22
overscan_right=34
#overscan_top=16
#overscan_bottom=16

# uncomment to force a specific HDMI mode
hdmi_group=2
hdmi_mode=87

# Sound output. Set to 0 or comment for autodetect, 1 for DVI, 2 for HDMI.
hdmi_drive=2

config_hdmi_boost=0

# uncomment for composite PAL
#sdtv_mode=2

# uncomment for lirc-rpi
#dtoverlay=lirc-rpi

# uncomment if display is garbled or slow
hdmi_ignore_edid=0xa5000080

In recalbox.conf, I only changed:

system.es.videomode=CEA 6 HDMI
global.videomode=DMT 87 HDMI

With the VGA666 board and transcoder, the setup was straightforward and effective. So, it would be great to have an option to switch to CRT mode "DMT 87 HDMI - 1920x240@60" (or something like that) directly through the menu system using Advanced configuration => Recalbox CRT, just like Recalbox RGB DUAL, VGA666, etc options in that menu... which are not suitable with many raspberry cases.

While this is a feature suggestion, I would be happy to resolve this problem by editing the configuration files.

Congrats for all team on the excellent work!