I've been having the same issue as well, the immediate second I went to my ccleaner app and just removed everything riot/valorant related my internet was back to normal. Whenever I play Valorant I can see in my Killer Control Center, (It's like an internet tool that tracks app usage for download and upload speed), that its taking up a ton of download and upload speed and literally for no reason, like I was trying my hardest to find out what it what was but I just couldn't seem to figure it out. It's like after they came out with that patch for Phoenix and Yoru everything was just so frustrating, discord wasn't working, chrome wasn't working, my phone wasn't working, everything was slow to the point where I just had to delete Valorant.