It's now been two weeks since Microsoft pushed out a new Xbox firmware update to target the deleted saves issue with Baldur's Gate 3 on Series X and Series S, and since then we've seen far less reports of the problem.
On the face of it, the issue seems to have been fixed, although we've continued to monitor the situation recently and have found pockets of reports where the saves are still being deleted. It seems to be happening a significantly smaller number of players now, but there's still a chance you could be unlucky and run into it.
As mentioned above, there's a potential solution to the problem in the form of a workaround that was shared by Larian Studios back in December. This requires you to activate cross-saves ahead of time via the Larian servers, meaning that if the worst should happen and your saves get lost, you can (hopefully) still bring them back via this method. Some people have had trouble with this, while others have reported it working successfully.
workstudywork on Reddit: "When I’m not able to see my save, I opened the option menu. Then I unchecked the cross save and turned it on again. Wait for the saves to sync. Later then you would be able to see your saves. I am not sure if this works for you, but it works for me now, for the moment."
It might sound disappointing that this BG3 issue isn't fixed for everyone yet, but we must stress that reports of deleted saves have dwindled significantly over the past two weeks, so clearly something has worked. For now, most BG3 players suggest turning off Quick Resume and quitting out of the game entirely as a precaution as well.