Server Version#: PlexMediaServer-1.18.2.2058-e67a4e892-x86_64.qpkg
Player Version#: unknown (last version from 2019-12-17 reinstalled)
After removing the client and re-installing it works some time (hours).
After leaving the client app and go back into there is an connection error.
All other devices (iPhone, Web) works.
Only the Fire TV Stick version sucks.
Update on server was done today. I had no similar problem before.
Best Regards
Chris