Phone slows down at random after MagicOS 9.0 rollout

Have had an Honor 200 Lite for 2 months, never had one performance problem, but after they rolled out 9.0 or whatever the last update was, my phone decides to slow down a LOT at random moments, screen will lose brightness and overall performance feels like it's at about 50% of normal. Has anybody else experienced this? How do I fix it to get my phone to work properly, am I cooked? Or do I have to rollback someway? TIA to anybody who can give me a hand on this