Gateway Network - Incoming connection certificate needs re-approval randomly

Hello, we have 18 incoming gateway connections on our server. Of these we have 2 remote gateways whose certificates suddenly require approval again. This happens occasionally out of the blue, and quite often if we restart the Ignition gateway that they are connecting to. Currently all gateways are running 7.9.13. I can’t put my finger on why only these two certificates will get booted from the approved certs.

Any insight is appreciated.