I have a weird PMP450i AP ethernet issue.
Its powered up Mikrotik CRS switch -> PacketFlux Cambium Sync Injector -> Surge arrestor -> PMP450i AP.
I have swapped the line feeding it with another different line feeding a different AP and issues followed AP not POE line etc.
It will start getting ethernet errors etc. at 1000base. Reboot the AP and it clears up for typically few weeks or more. In the Ethernet switch I try to lock out 1000base. It will not work at 100base. It will work fine at 10base or at 1000base with errors.