problems with backup - LR6 doesn't remember opened catalog from backup after next start

Hi, My name is Michael from Poland.

I have a problem with Lr 6.14 box version.

After my work with photos, I backup it and close Lr.

Next time when I open Lr, imported catalogs with new photos from previes work, is not displayd. There is nothing rembered.

So i go File->Open catalouge-> and finding my backup, After that everything is ok, and I have my photos.

But next time when I run Lr again, the same problem still exists. There is no my previes work so I have to open my backup catalogue again.

Can somebody help me and write howe to fix it up? What should I do?

I have been useing Lr from more than one year and there were no such problems earlier.

Thanx

Michael