Zarastro ,
Unfortunately, it happens quite often ..
Perhaps the most common reason .. an unstable signal from the distributing router to amplifier 2.
The solution here is one:
-we change the place of reception of amplifier 2 ..
- Theoretically, the case is not excluded when there is no normal contact in the power supply.
-But the main reason seems to be that the incoming Internet signal is weak and unstable .. despite the fact that the signal indicator shows 2-3 bars ..
First of all, check for Wifi .. reception at the installation point of amplifier 2 ..
Here the signal should be steadily caught .. for example, go to YouTube.