Hello everyone
I have a problem, my trains drive into the LTN unloading stations and only unload one grab arm movement and after that nothing is unloaded and the train stops in the station forever

All trains are now motionless in the unloading stations

Please post which version of LTN and factorio you are using.

if you activate the "stop timeout" setting, the trains will be forced out after the timeout has expired.

As to why your trains are not loaded, this depends on the station that you have built around the stop.

There is an "allows_unloading" flag in the train schedule but the current LTN release does not use it / changes it.