Won't refresh or add media/movies, circles 2 seconds but nothing new shows, nvida shield

PMS 1.41 removed support for legacy agents and plugins on the NVIDIA Shield.

If you were still using legacy agents for your libraries, those libraries could no longer be refreshed. As you pointed out, upgrading the libraries to the current-generation agents will fix this.
That’s why Plex had been nagging you for quite some time to upgrade the libraries.