Why is Age of Empires 2 HD Edition on Steam crashing during multiplayer constantly?

So I am not sure if this is the right sub or not just let me know and I will delete if necessary but please don't downvote as this is a weird bug I am having. Me and my brother keep trying to play Age of Empires 2 HD edition on Steam. It used to run fine a few years ago but for some reason our games constantly get interrupted. I am playing in London and he is in Devon (both in the UK on WiFi). Should I try connecting to Ethernet?

We never had the issue over wifi before but we can't even use the Steam chat because the Steam voice chat is so bad it's easier to talk over Facebook messenger chat since he doesn't have discord. I don't use it either so please don't suggest that. Thanks though. Basically I am wondering why the game keeps disconnecting. Our laptops are powerful enough to run it on Multiplayer before and this even happens when I play on PC. Is it just that the Internet is bad? (it's able to handle Battlefield 5 for me and other online games)

All our drivers are up to date and we validated the Steam files etc. I literally have no clue but the game crashed 3 times and said "Unable to Connect" It usually crashes like 15 minutes into the game or so right when we are building up a big army and trying to attack. Sometimes it lasts longer then that. Is it because there are so many characters on screen? We usually play with 4 other enemy AI bots besides us (both on the same team) just like casual on medium difficulty nothing too intense, lol.

Any reason why it's not working would be much appreciated. Don't know what I am doing wrong. At university I only used Ethernet since I had an Ethernet plug right on my desk and it had a very strong connection but we still had this issue. My laptop has built in WiFi with all the latest drivers.