I have now tested a USDT.BEP2 deposit and can confirm your findings.
The amount is deposited in the CP wallet, but the platform does not generate an IPN message, so the plugin is never notified. At the same time, deposits for other coins work fine.
I will continue to investigate and let you know if I find anything else.
In the meantime, do not use BEP2 coins in a production environment.