Comment 10 for bug 1874257

Yeah Dan, thanks for chiming in.
In particular that would be at least (but not lmited to) the changes:

8.04
Rework DTLS MTU detection. (#10)
7.08
Support automatic DTLS MTU detection with OpenSSL.
7.07
Automatic DTLS MTU detection.

Ubuntu has these newer versions.
Bionic 18.04 is on 7.08 and the most recent LTS Focal is at 8.05.
The current development release is at the latest 8.09 of openconnect.

These are new features added in 7.07 and 7.08 - IMHO they do not qualify for a SRU release into Xenial [1] - especially since you can "get away" with a config change that mitigates the issue.

[1]: https://wiki.ubuntu.com/StableReleaseUpdates