Android Marshmallow using up Internal Storage?

[KurtskyKG]

I'm using a Lenovo Tab 3 8 Plus with 64Gb Micro SD card

I the SD using Adoptable Memory which should make it
60+ Gb. Yesterday, I got low storage error and my internal
memory was at 15 Gb, SD card at 3Gb. I don't have much
apps and photos. 3 Games at 4 Gb each. Shouldnt they install on Internal?

I changed default location of some apps to SD but same issue.
I don't want to format again.

 

[Rukbat]

Low storage or low system storage? The system sits in a different partition than user data (which is where the SD card is mounted), so if it's low system storage, there's not much you can do.

Install a terminal app, like Terminal Emulator for Android, and enter the command

df

That will show you the various partitions, and how much space is used and free in each. If, for some reason, Marshmallow (the system) has gotten close to the limit of the partition it's in, you can try to boot into recovery and clear the cache.