Not sure if macOS gets these updates, but after the Spectre and Meltdown security vulnerabilities, Windows 10 patch made everything slightly slower. I noticed that chrome, graal, and many other games started to have these freezing issues, and fps drops.

Try to close any other programs when playing on PC (antivirus too, if you're still freezing)
For me, the game freezes when using the spotify web player, so if I spar I have to listen to music on my phone
Adobe is also ending flash support in 2020, so yeah