It took a week for me to realize I had to "update and restart" my laptop to get Ladder Slasher to work properly again.
I was deleting cookies and everything. LOL, but I never restarted my system. My cooling fan works better always on.
Good luck playing again. I was addicted to Ladder Slasher for most of 2020, but I died a month ago and it's been tough for me to play again. Hopefully soon I can rediscover that passion for Ladder Slasher (I'm not feeling it yet), but I started playing Diablo 2 again for nostalgia. The 20-year anniversary for D2 classic is next month. I also play Diablo 3 and Heroes of the Storm.