Found this topic:
Which pointed me to the old app, Plex for Android - #525 by PlexAndroidReleaser
1- removed old app
2- downloaded the [Google Play (arm64v8a) 10.26.0 version for my Samsung Galaxy S10 Exynos from this link: Plex for Android - #525 by PlexAndroidReleaser
3- installed and logged in
4- Disabled auto update for this app in Play Store for Plex app.
Obs: In Android, when you click “update all”, it will find that Plex app auto-update is not set (disabled), and will ask if you want to update it anyway, just click: “Ignore”, and it won`t update Plex while updating all other apps in the phone.
Thanks, can close this thread.