I have same problem with MAC M1 Max with 64 Gb or Ram. The maximum available at the time of launch.
The activity monitor shows that all CPU and GUP is used by word and very slow. I wonder if this problem is due to ARM processor not being compatible with microsoft.
I updated to new version, at beggining was working well 1 week then started doing the same. Every minor change i do, the file starts loading and get stuck, then sfter long wait i can use again. I use the mouse for a bit and then again the same loading and getting stuck. It is burden having to deal with this.
Version 16.89 (24090815)
I was advised by my university to run an update which i did, then I also updated the IOS to newer version, still same problem. I have lates word and latest MAC ios, nothing improved.
i really need your help, it is impossible for me to do anything like this.