It could simply be a lag issue. I doubt that the Bluetooth receiver in the Pie3 is as robust as the PS4 one. For this reason I don't use more than 2 PS3 wireless controllers at a time.

The only related issue I could find is this one, but that's more about power draw from the controllers than Bluetooth lag:

https://retropie.org.uk/forum/topic/6756/solved-ps1-controllers-random-input