@tdelios Just a single file per MAME version/folder, a lot less annoying than changing the core for every single game using the UI menus.
And no, there is no plan to split MAME into version.
Recalbox is currently supporting AdvanceMame, MAME2000, 2003, 2003+, 2010 and 2015 (maybe more in the future). It would be even more confusing than having a single folder.

@bkg2k
Thank you very much for your attention and help. I even looked at the log and had not identified anything strange, but after reading @voljega's instructions and making the change on the command line, I saw that the log contained a part that was -system cps3 -rom

I was able to solve the problem.
Thank you very much for your help.