We had a support case were it turned out the cause of an S/MIME certificates "invalid" status was a missing proxy setting.
To make it easier to debug this kind of issue in the future, we would like to add a test in Kleopatra to check the connectivity.
Edited on 2025-05-14 (removed alternate options, expanded on chosen one)
Please add the test to the self-tests, but only as optional test, which would have to be checked at the bottom of the window to include it.
Put the option "Include online check" with default 'no check mark' below "Show all test results".
All configured servers should be checked and if version.gnupg.org can be queried.