Lots seem to be having similar problems of late. It's a case of trying to find out who's at fault:
Internet provider blocking
The box/stick
The program
The VPN
Or the server itself.
I've noticed Tivimate is not as good. I took a server I had and put it in Stalker Player 1.34 and it worked fine with only 2 freezes in the whole Liverpool game, a simple channel change sorted that.
Tivimate of late seems to be buffering like the magic roundabout.
I played around with buffer size and external players but it either made no difference or it just made it worse and froze solid.
I used MX Player VLC Stalker Player, you name it, I tried it. For me I still find STBEMU to be the most stable.
I think its trial and error but I gotta admit its getting harder and harder to keep it running smooth especially at peak football times.
I use Analitic speed check. I tend to use Belgium Germany, Holland on with Nord VPN.
I start the VPN come out then check it's speed. I did it the other night and Germany was 3mbps on a 2meg line. When I selected Belgium it went to 120mbps so it's worth checking.
I always unplug-reboot the router before a game. Not sure if it works but I seem to have less buffering.
And,
mine are all hard wired as well.