I am constantly getting disconnected in middle of games. It's very weird because it doesn't happen when I'm not playing or when I do other stuff on the Internet(like play online chess, watch streams and so on). I tried to reinstall Voobly, checked my firewall(AOE2/Voobly allowed), change UDP port, but this annoying issue continues. Any suggestions or anything that could be useful? Thanks in advance.

In the majority of the cases, mid-game disconnections are attributed to a connection drop. When playing on Voobly, you do need a consistent and stable connection to the Voobly server and internet in general. A minor drop in connection while browsing the internet or watching a youtube video will have no effect whatsoever however, it can be enough to get you off your game on Voobly.

If the game starts off fine and you abruptly get disconnected mid-game, assuming you are not playing a 1v1, you can be sure that you have a problem with your connection. Firewall is a less likely cause but must not be overruled. Drop in connection can be caused by a variety of reasons including poor connection, faulty cables, bad router/ modem, etc etc.

If you are using a wireless connection to your router, try connecting to the router via a direct cable instead while ensuring wireless is turned off. As a test you can also try to connect to a different network (another wifi) or a mobile hotspot to see if the situation is any different out there. This will help you narrow down the problem cause.

P.S: Mobile networks aren't ideal for gaming on Voobly and must only be used for testing purposes.

I'll try those tests when I have the opportunity, thanks for the answer. The only thing that makes me think it might not be the Internet is because it seems to have no problem for other things that require stable connection. I can watch live streams and play bullet chess(and I'd definitely a drop as it would most likely mean losing the game). Is there anything else I can try?