Slow minor editing adjustments in lightroom on Mac Mini M1

Hej! I need help to understand what is the issue with my computer, and running lightroom specifically. Photoshop is no problem outside of opening images to edit from lightroom directly. 

In lightroom any small edit adjustment brings up the dreaded spinning wheel and the situation I think has gotten gradually worse over the last months. I tried to make some adjustments and clear some space - for example moving my dropbox to online only. 

I suspect it is the computer - but perhaps the external drive where the images are stored? 

Here is the file with the system info. Any help appreciated.