https://www.gsmarena.com/samsung_galaxy_tab_s6-9781.php
Try going into your Settings >> Apps menu, find and open the Google Play Store entry, go to Storage and tap on Clear cache. Do the same thing with the Google Play Store Services app. See if that made any difference.
If you're still having a problem with the Play Store, instead of Clear cache tap on Clear data instead, and then be sure to restart your tablet. This is a bit more invasive than Clear cache (cache files are all just temporary 'working' files the apps use) but keep in mind that the 'data' you're wiping in this case is just background data files that those two apps accumulate as Google monitors your tablet's Play Store activity. The point being, it's not data you can use or need for your usage. It's for Google's usage. Basically your Google account exists online within Google's server farm so that's where your Play Store actions get retained.
Anyway, if that doesn't help either the problem apparently isn't Play Store related but perhaps some third-party app/service is inadvertently messing up the Play Store service on your tablet. When did this problem start occurring? Is it a long-standing issue or just recently?