Hi all, thought I was going crazy so did some checking today to ensure I was correct.
I setup a clean 7.22 install on my Pi4 on a spare 32gb microSD, and have every single bios file for every emulator.
I then copied over all my MAME games and folders, and tried my 66 working light gun games in MAME (I have them in their own dedicated sub folder).
Every single game worked, with some obviously requiring me to go into settings and ensure the 2010 or 2015 emulator is their default when running (eg Area 51, Point Blank).
I then did an online update to 8.02, and now of those 66, 43 do not now work. Literally, only a third of the games now work when all I have done, is update to Recalbox 8.
The games still attempt to use the cores as defined under 7.22, so it looks like the only way to use MAME is to re install the old version.
And its not obscure games that arent working - its games including Area 51, Point Blank, Point Blank 2, Lethal Enforcer etc.
Can anyone confirm what has happened ?
Many thanks.