/run/flatpak/doc/83840e7a/imap.freedom-1.nl

I use thunderbird on Ubuntu 24.04. My emails are on a network drive for at least 20 years. Recently Thunderbird must be installed from snap or flatpak. In both cases I can still select the mail files from my network. But in both cases the path to my mail file is garbled like: /run/flatpak/doc/83840e7a/imap.freedom-1.nl But thunderbird still can find the network files after a restart. However, when rebooting the hex part of the file path (in this example 83840e7a) has a completely different number. The result is that thunderbird cannot find my mail anymore. How can I solve this issue?