sometimes when cleaning bookmarks in browser TAB mess is created :-(

yes, in 90% all family members use firefox, but one never knows what will be in future ;-)

yes, I am thinking about that, but I did find out that for sync it is easy to start own server but for account management it is hard, so maybe I will need to used mozilla one

thanks for good tip

on server you could try

https://radicale.org/v3.html

to sync calendar and contacts on android you can used davx

and simple calendar app is nice https://www.simplemobiletools.com/

yes, that’s clear, I am trying to avoid that.

before I did start to use my own domain I did used duckdns.org as many people. well, maybe they did open / forward ports to local server but if not then same problem occur.