@james-anderson Hello!
Even if you have tried more than one extension, it is still possible that it is a ROM with some Bug.
Since the ROm is good, searching the forum, you find this topic:
https://forum.recalbox.com/topic/8753/bugs-graphiques-jeux-psx-xenogears/8
OR, translating with Google translator:
https://translate.google.com.br/translate?hl=pt-BR&sl=fr&tl=en&u=https%3A%2F%2Fforum.recalbox.com%2Ftopic%2F8753%2Fbugs-graphiques-jeux-psx-xenogears%2F3

And what is suggested by rockaddicted is:

delete the file: /recalbox/share/system/configs/retroarch/retroarchcustom.cfg the latter will be regenerated, so no problem. edit this /recalbox/share/system/configs/retroarch/cores/retroarch-core-options.cfg file, search for pcsx_rearmed and delete all references to it, save and exit.

You can do all this directly from the local network share (or ssh if you are comfortable).

@Rival187 J'étais loin d'être un vrai gamer, et il m'arrivait souvent d'acheter des jeux au méridien...
Je me souviens tout de même avoir limé les bords du port de cartouche de megadrive pour y faire entrer altered beast en import jap. Le zonage, à l'époque était facile à contourner !

@matthieu-champion parfait, have fun