collections i LR desktop dissapeared

I have both collections and collections set i LR desktop, that I have synced til LR mobile (both on Iphone and Ipad).

After being away for desktop some time, I want to work in LR desktop, but now all my collections are missing, only smart collection and collections from LR mobile are still there.

The missing collections are still shown on my Iphone and Ipad, but not shown on the LR desktop.

After sync with LR mobile, the collections are shown in collection LR mobile, but not as the collection set I created on the  desktop. All collections not synced with LR mobile are gone

Whats wrong??

Best regards

Anne