I admit to being caught napping. My high-powered custom built Win 10 suddenly bogged down and finally stopped responding. I took it to the builder. Now, I routinely pause the monthly updates for a few weeks and wait to hear of problems, then update. I do not and have not updated, though, to a newer version. The tech said that was a mistake. He totally updated and that solved all.
Am now running
21H1, and OS build 19043.1320
I also had a couple of minor crapware programs he removed.
Lesson Learned....I hope!