Need new neighbors

The OP is asking for new SFP neighbours - this can only be done via FB. I think this has been a deliberate decision by EA rather than a glitch, but they're not very good at making this clear and taking down old guidance for other options that no longer apply.

I've been round the houses on this numerous times in the past. Adding friends on GC and GP doesn't help with neighbours, so I'm just trying to save people from wasting time.

You can still add friends on GC and Google Play.
minicha-em pointed out that those friends don’t show up as neighbors on the Party Boats.
I didn’t see mine for five years already and I doubt that Apple and Google Play will fix this any time soon, if at all. 

I'm pretty sure you can only add Sims neighbours via FB

ID can not be used for adding friends PaneneLumps​ EA might add the option to use the game name but never the ID

You should treat your ID as your social security number . do not share on open forums

You can add friends on FB, Google Play or Game Center - only Google Play is safe to use here since the others require personal information to be shared. Though both Google Play and Game Center are so neglected by Google and Apple that you might not see the new added friends for some time, like aa month or never