Contact time zone "Europe/Zurich" saved as "Europe/"

[l0b0]

I just created a new contact in Thunderbird 136.0, and set their time zone to "Europe/Zurich". After saving the contact on a third party server running sabre/dav 4.6.0, I exported the CardDAV address book in vCard format from "https://carddav.OMITTED/addressbooks/OMITTED/addressbook/?export". But the time zone just shows up as "Europe/". So either the form data is being handled improperly by Thunderbird, or sabre/dav is handling it improperly.

This is the dual to the associated Thunderbird issue, since I don't know whether the issue is with Thunderbird or sabre/dav.