Interesting, added my ISP to my previous comment (Vodafone). Do you have a lot of stuff you use daily that goes away during the games? Personally the only thing that seems to stop working is Docker Hub, everything else seems OK, trying to figure out if it's just my ISP that is lenient or what's going on...
It changes depending on the day. But yes, some days it's really a lot (affecting forums, news sites, etc.). I think Movistar applies stronger blocks than most for some reason, in fact I've been seriously consider changing ISP for that reason but I'm too lazy (plus in 12 years with them I think I've had a single outage which was solved in an hour or two, so even if I oppose them morally, it's convenient to stay...)
Not bandwidth priority. It's just that our brilliant judges have let the football league implement IP blocks to combat piracy of football matches. These blocks affect CloudFlare IPs that host many websites and services unrelated to football, so we can't access them during matches via VPN. (And by the way, I'm not interested in football but people I know who are say that they still view pirate match broadcasts just fine).