I have found the issue.
Super Bomberman 5 is missing in the list of multitap supporting games and therefore Settings.CurrentROMisMultitapCompatible is never set to true.
Adding the line MATCH_ID("A5SJ") || /* Super Bomberman 5*/ (after line 3146 for example) in the memmap.c file will fix this.
I have found the issue. Super Bomberman 5 is missing in the list of multitap supporting games and therefore
Settings.CurrentROMisMultitapCompatible
is never set to true.Adding the line
MATCH_ID("A5SJ") || /* Super Bomberman 5*/
(after line 3146 for example) in thememmap.c
file will fix this.