Off course, but I was not acting as a developer, I wanted to end this abnormal behaviour by any means. I had an argument with Apple support because I doubted there can be a proram which has the power to screw up any other program running on the machine. Yes it can, I learned, and it happened via the Spotlight Indexing. It froze every saving for 20 seconds.
First I switched off the database spotlight indexing within devonthink, and i got the feeling this solved the problem. Then I put the database folder on privacy to exclude it from spotlight. And whatever which solved my problem, its solved. I can use both devon and my mac again.