I have a Samsung Galaxy s8+, and since the game updated earlier this week, it has been "Pending..." in the Google Play store. I uninstalled the game thinking a fresh install may fix it, but it did not. And yes, I have plenty of space, over 60% of ny storage is unused.
First make sure no other apps are trying to download or update. Including software for your phone. Once you ensured all downloads are stopped, try going for the RS app again.
If this doesn't work, perhaps you've gotten a VPN? Try turning it off.
Perhaps your Google play storage needs cleared?
A few different options to try. Give it a quick online search for anything more specific.