Форум поддержки Firefox

My Windows 10 PC stopped working a few days & is disconnected & partially disassembled. I’m temporarily using an old Windows 7 PC which I brought up from the basement the following day. They both have Firefox on them.

I saved one bookmark on the Win7 PC today. It was there when I looked earlier. Now I went to use it again & it’s not there. But my Win10 bookmarks are there!!

How could that be?

Meine Android App Firefox ist gestern eingefroren und ließ sich nur neu installieren, nun sind alle Firefox Lesezeichen und offenen Tabs weg. Wie bekomme ich diese wieder???