I'm seeing exactly the same issue. This is only a problem when the "off the grid" lot challenge is active - I can work around it by turning the challenge off, adopting the pet, and then turning the challenge back on (all without changing/resetting the game). I have over 200 surplus energy stored and all other electricals work so it is not down to not having sufficient electricity to run the phone. I can make the selection in the phone menu but it then disappears from my sim's queue without them doing anything.
I don't know if a particular patch caused this for me as I have not played an off the grid scenario before where I have also tried to adopt a pet. This is a new save file though.
I have all EPs, all GPs except Star Wars and most of the SPs. I also use MCCC mod but no others.
