It looks like this bug https://bugs.webkit.org/show_bug.cgi?id=202589 got back. After upgrade MacOS to Big Sur -> safari version 14.0.2 I see the same behaviour as in the above bug. Calling the method click () performed w/o any exception but nothing happens. I've checked STP Release 118 as well and it contains this issue as well . In case it's needed some additional information let me know.
All work as expected on safari version 14.0 MacOS 10.15.7
Per originator, problem no longer reproduces. Please reopen if this is incorrect.