I use this splitter on an OLED tv that only has 2 HDMI 2.1 ports. Works without issue for my PS5 Pro, Xbox Series X, Switch 2, and PC.
UGREEN 8K@60Hz HDMI Switch 5 in 1... https://www.amazon.com/dp/B0CPF4ZQM8?ref=ppx_pop_mob_ap_share
This exact same thing happened to me. Same mouse. Same dongle. The cause ended up being the dongle was too close to the WiFi antenna and kept causing interference. Once I move the dongle away, smooth as silk.
I don’t feel bad about the Bills call. The game should never have been in OT anyways. They held the Broncos when Allen was in the end zone. That’s a safety and the game. Plus, we’d still have our damn QB.