Android - Weird bug with applications uninstalling themselves, can't install on internal sd card

[ottr]

Guys I have the most peculiar bug on my Xperia Z2 running a chinese rooted rom on Android 5.0.2.

I just assume this is the best thread to go to. Basically, when I install APKs they don't work and/or uninstall themselves. For example Pokémon Go works for a bit after I've installed it, then it crashes and uninstalled itself. I do have an external SD card, and they seem to prefer putting themselves on it. Naturally I assumed that means there's something wrong with the card, so I tried to move the apps from it onto the internal storage ( with 2gb of free space, and a free cache ) using Link2SD, but it says "Invalid Location"?? If I take out the SD card and try to install these apps, I get an error stating there's not enough space on the drive. Even though there's clearly 2gb available according to the system