This bug is a regression in libserf-1-1 version 1.3.9-10ubuntu1, which switched to OpenSSL 3.0. Version 1.3.9-10, which uses OpenSSL 1.1, does not have this bug.
Using version 1.3.9-10ubuntu1, Subversion, which is the only dependant of this package in the Ubuntu repository, breaks when using the https protocol. For instance, the command...
svn info https://svn.apache.org/repos/asf/subversion/trunk
... will no longer work and, depending on the server, may close the connection or return some sort of error.
Attempting to analyze the problem in wireshark, I discovered that the TLS traffic generated by libserf is malformed and cannot be parsed by wireshark's packet disassemblers. At a glance, it appears that libserf is sending a raw TLS Client Hello without first sending a TLS record header. For instance, to use the illustrated handshake example here [1], the handshake that libserf generates appears to be missing the first five bytes (the TLS record header) and instead begins with what the illustrated example calls the TLS handshake header.
[1] https://tls.ulfheim.net/
Status changed to 'Confirmed' because the bug affects multiple users.