Where are my tags?

Where are my tags?

I updated this morning to the new Windows Desktop version (10.0.24). After that I checked and most of my tags were GONE! In the list of tags as in the respective notes. I went to the Web version and ... horror... same thing. Only a small percentage of the tags is still there. 
And in "Activity Panel" it says that I changed hundreds of notes in the last hours. Which I didnĀ“t. 

What the heck happened?