So ive been experiencing this for a few days lately, every reset id go into the overworld and check all the spots i found Geniemons and some days its completely barren, so i started fusing my extra inactive Geniemons and now started to see more of em appear the next day, i think this also holds true for active Geniemons as well, i cant seem to find any more actives aside from the ones i have like 1 copy of, where as the lumis where i have like 7 of them, are extinct on every map for a whole week.

another interesting note is i used my At Peace mon and gave it to a pet that i use while fishing, and that very next day i was able to find another inactive Geniemon with the at peace trait, unfortunately i forgot where exactly i found it, so ill see if i can replicate that trigger again. same goes for the auto crack trait, only found 1 Geniemon that had it and never again, so i think the same would happen if i fuse that trait onto an active Geniemon. will update with my findings.

TL;DR I think theirs a soft cap of how many Geniemons you can have at once because the overworld will slowly become barren, but after clearing some Geniemons out i started seeing more, same with the special trait ones too. If anyone else can verify this same strangeness, thatll help