Can't exclude app from battery optimisation

I have bitdefender installed as I have a package for my family’s devices. However, it keeps getting turned off and the only reason I can find is battery optimisation.

None of the methods I can find to exclude it from battery optimisation are available. There are no ‘three dots’ or ‘more’ option in my ‘battery’ settings. It is already prioritised and given all permissions and turned on in accessibility. It is set to have unlimited battery usage, display over other apps, everything.

The only thing I have managed to find was something telling me that I couldn’t exclude that app from battery optimisation. Frankly, I don’t appear to be able to exclude any app whatsoever from battery optimisation.

Any ideas?