If you connect your notebook to LR mobile using the same Adobe ID you used on your desktop is has Un-synced all your collections you made on the desktop and your phone.
LR Mobile is only for syncing One Computer with One Catalog on that one computer to multiple, one or more, Mobile devices. It can not be used to sync multiple Desktop/Notebook computers to each other or to mobile devices at the same time.
This is also true using the exact same catalog on different computers. Every time you move or copy a catalog to a different computer it gets a Unique ID number and it is that number that is used to sync with LR Mobile. Different computer same catalog file = different unique ID and syncing with LR mobile will wipe out the other sync.
All you can do is go to the main Adobe page, Sign in with your Adobe ID and go to the LR Web gallery and see if all your collections and images are still there.
Thank you for the prompt feedback.
I understand better now. I understand that LR sinchronised with the laptop, which had no shared galleries, meaning all shared galleries are gone. (The LR web gallery is also gone.).
I still have some questions:
-later today, back home, when I will start LR from my desktop computer, will the sync master be what is currently online (=no gallery) or what is on the LR desktop computer (=previous shared galleries)? And if the sync master is what is currently online, how can I make the LR desktop computer taking the lead and becomming master for the sync?
-why on my mobile phone I can't get LR mobile accepting to bring the existing pictures from the phone in the LR mobil library (Android)? When I use the function "import", LR mobile doesn't show the pictures from the phone...
I thank you for your support!
Not sure on the first question.
I once tried what you did thinking I could sync my home desktop to my phone and then sync my personal Work notebook to my phone and the desktop and what happened is exactly what happened to you. With that I deleted LR Mobile from my phone and said Good Bye. IMHO LR Mobile is a bad joke being played on LR users.
Sure Adobe allows you to install LR on 2 computers but NO you can't sync those 2 computer together is any way. Then they come up with LR Mobile so you can sync to multiple Mobile devices but you still can't sync the 2 computers together.
I just copy, import, Synchronize folders after using a Computer Sync program I've used for years. And as far as my phone I use it as a phone and work email system. I rarely take images with it. I rarely use it to show images to anyone. So no big deal for me.
If I need some images on my phone I just copy them to the phone or send them to my work email address. Simple and effective.
Oh and to the second question I have no idea. See the Joke part of my reply above.