Umbrel freezes when playing video via Jellyfin

Device: Raspberry Pi 4B 8GB
Ethernet: cable
Drive: SSD (1TB Samsung T7)
32GB U1 SD card

I use Umbrel with couple of apps installed. When I do play video via Jellyfin, it works fine, but after couple of minutes - video freeze. When I investigate what happend, I find out the network is slowed down - if i do download of the video to my computer it is downloading of speed couple of KBps. At this point I have also problem to open Files app (the same problem i think).

When I restart the divece, everything works fine again, until i play a video via Jellyfin.

Any idea whot could be wrong? Is it possible that there is a HW problem?