Any app which uses WifiManager (the way an Android developer talks to the wifi driver and supplicant) in Android can conflict with Wifi Fixer. Usually it’s only the ones that intercept scan results or set state or locks. There’s really no good way to avoid this type of conflict, as there’s no way to really tell what another app is doing.

Y5 battery saver seems to have a serious issue playing nice. There’s likely nothing I can do about it, but I’m looking into it for the next version (not, to clarify) of Wifi Fixer, and I just wanted to confirm the issue in case anyone was having it.