*edit*
i figured out the cause plus a fix and share it with you. its because the mi box (as all other oreo devices) wont shutdown completly (instead hibernates) and when waking up it always told me that the adopted storage was removed (due to power outage in hibernation) i found out that this actually is not happening when the sdcard adapter is plugged directly to the mibox usb port. instead i had it plugged into a 4port usb 2.0 hub which seems to not work as expected with my sd adapter. i replaced it with an usb 3.0 hub and now after hibernation the adopted storage is instnatly found. i read at the xiaomi forum that there is a good chance the sdcard will get corrupted if i have this dialouge to often (adopted storage is not found). first i thought a reboot of the box would be enough, but theres still a chance that the sd card gets corrupted during this "process".
*edit*
Hi,
i just rebooted my MiBox S and it took forever to load. Now like half of my installed apps are gone. Also many files are missing. It doesnt matter when the app was installed, they are lost randomly.
There are even no more default folders like "Downloads" and so on. Im using an SDCard formated as internal Storage.
How could that happen? Any ways to restore my lost data now? Strange thing is that it shows that 2GB are used on the Drive and as far as i can remember thats about what i had installed. But i cant see them and they dont show up anywhere.
Please help!
Sounds like your card died, if so, there's no way to restore it or its data IME.
That's why they've not recommend using flash media (thumbdrives/sdcards) for alt internal storage for some time now.
Put your memory card in your PC, if you can't reformat it/it's locked up & read-only, then there's nothing you can do but get it replaced, if you have coverage on it or its a high end type card that has a built in warranty for 5 or 10 years.