Steam remote play poor quality on linux as a client

I get very poor video quality (pixelated) when playing games from my laptop via steam remote play on ubuntu 20.10. When I use the same laptop, with the same settings on win10 - the quality is excellent.

My infrastructure:

• steam server: win10 with rtx3070 (connected via Ethernet to router). Steam uses hardware encoding.
• steam client: lenovo x1 carbon g6 (win10 and ubuntu 20.10) (connected via 5GHz wifi)

As I connect via Wi-Fi, first thing was to check network performance, on both operating systems I'm able to get avg 3ms pings. Using iptraf3 to measure throughput: win10 gets avg 90Mbit/s, ubuntu gets 240Mbit/s. Let's say it doesn't look like a network problem :)

I tried both software and hardware decoding, there was no big difference. I tried to play with limit bandwidth settings but even with no-limit there was still a lot of ugly pixelization on linux. Setting client setting quality from balanced to beautiful also didn't help.

Here is screenshot of steam performance overlay from both systems (win10 as a client and ubuntu as a client):

As you can notice, frame drop is quite high on linux side, but what is the reason? Also the incoming bitrate on windows is way higher (so no compression artefacts like pixelization), but how can I enforce steam on linux to use more bandwidth?

Please help me track the issue down to the rabbit hole. I would like to be able to play my games from my linux laptop :)