I have been using Fusion for a couple of years now and have never managed to get this issue resolved.
I run a Dell 7410, Windows 10, Office 365 Semi Annual updates and Fusion 2022.
If I open an Excel with ~1000 rows then Excel will slow down to a crawl/become unresponsive. As soon as I disable Fusion, the system comes back to life.
I still have some sight, so I tend to just close Fusion and used Win10 Colour Invert to work around it - but obviously this isn't a good long term solution.
I have this on many sheets, including new sheets I have just created. I have also seen it when the file is local on the C drive and when Synced by OneDrive, as I know OneDrive Sync can slow things down at times.
Does anyone have any ideas on what might be causing the issue?