Note: When the Rockstar Cloud Services are unavailable, you are given the option to still play online on disc-based content (rather than R* Cloud content). You are asked to confirm before entering Multiplayer whether you would like to play on a temporary character, without the ability to save. If you confirm this option, please note that none of your old characters will be available for that play session, and the temporary character you create will not be saved. If you want to make sure the characters you create are saved, you should not proceed into GTA Online when the R* Cloud Servers are unavailable. Even if the services come back up while you are playing on a temporary character, that character will not save -- you would need to return to Single Player and re-enter GTA Online to load your non-temporary characters and resume playing with the ability to save progress.
Note: When exiting GTA Online, please pause the game and choose to return to Single Player. This will trigger a save and ensure that progress since the last auto-save is recorded. If you purchase items and immediately power the console off or exit through console system menus, those items may not be saved.
This should help if you are still losing characters.