Magic mouse and keyboard acting weird

hello Grant, you are so right. I had just fixed the problem when I received your post. When I tried a different keyboard and a different mouse from a different company, they just continued the same problems. Apple support couldn't identify the problem and a supervisor told me it was the computer and made me send it to Ottawa to my brother-in-law to take to an Apple-store. They wouldn't let me ship the computer to them since it is too expensive. The genius bar in Ottawa could not identify the problem (and they were right the computer was fine) so $300 later, just for transport, the iMac Studio came back to me in the same state. Purely by accident or just a coincidence I was able to get into the settings, and I (disabled) disconnected the Apple mouse and the Apple keyboard. The standby keyboard and mouse are now working perfectly, and no longer reproducing the same problems. So you are absolutely right, Apple support should've started off by disabling or disconnecting before trying with another product. Sometimes, the most complicated problems only require a simple solution. Thanks so much for trying to help.