You are using AD import of resources from 2 domains:
int.main-example.com
int.other-example.com
After the AD import, there is only one Notification Server Filters/Directory Filters/domain/*** folder created which contains all filters belonging to both domains.
ITMS 8.6 RU1
Known issue. The internal logic during AD Import was not considering the remaining naming values after the first portion of the domain name. In this case "int":
int.main-example.com
int.other-example.com
This issue has been addressed in our next release: ITMS 8.6 RU2
A pointfix for ITMS 8.6 RU1 is available under KB 221269 "CUMULATIVE POST-ITMS 8.6 RU1 POINT FIXES"