my link has this issue, when someone talks on the repeater, the node keys up after the repeater unkeys and sends a CT.
i have the link set to duplex 1 but it still does it.
Sounds like your COS logic is inverted from what it should be.
If you are COS’ing a hardwired repeater and using the PTT line to COS on repeater,
You will have to invert the logic there, likely with a transistor.
PTT output line is normally 0v (float) when inactive and 0v (grounded) when active.
So, you can see the issue if this is the case.
i was able to solve the issue by extending the rx and tx delays