Thunderbird retrieves incorrect certificate if server address contains port number, when connecting to network calendars CalDAV or address book, CardDAV

[kubuntu-newbie]

When creating a new account for calendar located on the network, if the location URL contains port number (https://nextcloud_server:port), I get an error Add Security Exception, "the certificate belongs to a different site", because Thunderbird pulls certificate from https://nextcloud_server (which shares ip address with a different server with different name) and not https://nextcloud_server:port which is running my nextcloud instance and has the correct certificate.
If I push the button Get Certificate with the location (which shows :port in it), I get the correct certficate and the option to Confirm Security Exception is grayed out. If I now Cancel out of the dialog I still can't connect to the server and if I don't "get certificate" and just try to "Confirm Security Exception" it doesn't seem to work and I get an error again when trying to "Find Calendars"

This is not a very unusual configuration since I'm running my Nextcloud (https://nextcloud_server) in a "docker" on a TrueNAS server (https://truenas_server) and the only way to differentiate the two is by supplying the port number. Both servers share the IP address and my local DNS server has aliases that point to that IP address. Each server has it's own certificate and Thunderbird pulls TrueNAS server's certificate ignoring the port number which would result in a correct certificate (which it can pull in the error dialog but it doesn't "stick").

Thunderbird version 115.14.0 (64-bit) running on Fedora 40

This problem didn't exist on the previous versions of Thunderbird, I'm not sure exactly when it started, most likely no more than 1 or 2 versions ago