Painfully slow to save project V3.5.1

To save a one hour project takes 8 mins to the the save then 26 minutes to compact , so well over half an hour in total. Laptop with i7, SDD and 8GB ram. Checking using the performance monitor shows CPU 3% and SSD 0% activity.

I see a few people have had similar issues but no indication of a resolution.

Anyone any ideas? Ta!