look this guide:
https://www.drac346.net/2018/12/atlas-dss-guide-building-map-pt-4.html
https://docs.google.com/spreadsheets/d/1a-9t4KwN8_kKEg4n6tZcqLsv8p4ce2Kjaoh1Tu2LKMs/edit
I confirm that, i have the same problem..
After setting EndBossLevel in extraSublevels animals dont respawned, now i delte the "EndBossLevel" and we have a respawn problem ...