Installation stopped at 0%

Have been playing NBA2K20 fine since late 2019. This was a disc installation, not purchased through Game Pass. Then got Game Pass on 25 Jun 20 and within a week could no longer play. Gave an error saying the game needs to finish installing or ready to start
when it wasn't even installing. Followed MIcrosoft Xbox One related fixes including un/re-installing game, off/on, unplug, clear local saved games, offline/online, signed out and back into Microsoft/Xbox account, etc. Getting "installation stopped" at 0%.
Same thing happened with FIFA2017. Other games that we actually got through Game Pass that initially worked fine but then suddenly stopped within approximately 10 days include Lego Star Wars The Clone Wars III, Cluster Truck, Rocket League, Batman Arkham Knight,
and Football PES2020. Game Pass expired 9 days ago, tried the above fixes again to get NBA2K20 working but still to no avail.

An Xbox Gamer (via Microsoft Support Contact) advised to do a console reset selecting "keep games and apps". Did that and FIFA 2017 installed. Unfortunately, NBA2K20 remained at "installation stopped" at 0%. Same result when we tried to re-install NBA2K18.
Therefore thought the issue may have been isolated to 2K Games.

Based on this assumption, purchased Lego Star Wars The Clone Wars III (Xbox 360 game) yesterday which my son enjoyed via Game Pass, but which we got the same "installation stopped" error at 0%. Paid nearly AUD30 for this "oldy but a goody" yesterday only
to get the same "installation stopped" error again! So bloody infuriating, and makes me uncertain whether this is a Microsoft issue, a 2K Games issue, or a combination of both.

Again tried to clear local saved games (including the XBox 360 option), turn console off, unplug, turn on, go offline, unplug external hard drive (~500GB of free space), all without success.

Summary - get the same error for game being installed from disc as I do purchased from store (and previously, via Game Pass). Same error for Xbox One and Xbox 360 games. Console reset choosing the keep games and apps option did not resolve the issue. However,
Forza Horizon and Minecraft continued to work fine through all of this drama and frustration.

What I would like is for my son to be able to play the games that we bought for him, and that he purchased with his savings. He loved playing the game as an individual, but he also really got into managing his team, doing trades, etc. It was awesome, so
not being able to play is extremely frustrating.

Any suggestions would be greatly appreciated.

:)