[2.0.73] Map download problem

[acreir]

I have a headless linux server which i normally play the game from with my friends, and the save file is 35 MB.
Around 1-2 days ago, we got disconnected randomly (it started lagging, then we got dropped from the game one at a time) and we cannot connect ever since because whenever we try to connect, it gets stuck at map downloading, the download speed starts at around 70 kb/s and drops to 0 quickly. (Our internet speed is not a probem, both the server and the clients have around 1 gigabit download and upload.)
I retrieved the save from the machine, hosted it with steam and it seemed to be working fine (the download speed is maximum 700 kb/s for some reason) and we were able to connect.
we tried these:
1) restart the machine
2) disabled QoS Packet Scheduler on the server’s network adapter
3) tried a different machine to host the server
4) tried to join the server using steam and LAN
5) Increase UDP buffers
6) tweak server settings config

[Kalixt]

I have similar issue, downloading a map (170MB) is slow compared to what server connection is capable.
I have tried speedtest and bandwidth test with other microtik on the internet and server speeds are 160/160 mbit, yet clients downloading a map with maximum speed of 16-32mbit.

CPU and disk usage while client is connecting is normal, there's no HW bottleneck.
What I have yet to try is revert version back to two or three months ago and try again, because this wasn't issue few months ago. (sounds silly but you never know)

EDIT: I've tried version 2.0.60 which dates back to jan 2025, so its just my problem...