Tilemap sprites fracturing and completely unusable?

I have been having some sever problems with getting my tilemaps to be usable, with the full tileset being invisible and some weird tearing when hovering over the area they should be. When the tiles are placed on a grid the same effect applies.

some examples: unity tilemap breaking - Album on Imgur (these were taken in the tile palette)
The tilemap I want to use: Imgur: The magic of the Internet
I have tried a few things to fix it: Remove the gradients and reimporting, add a white background instead of transparency, export it from Photoshop instead of GIMP which I initially made it in and nothing has worked.

I am using unity 2018.3.8f1 personal

Any help is appreciated.

After some further testing I have solved the problem.
The cause are the preview packages 2D animation, 2D inverse kinematics and PSD importer im not exactly sure why these cause this but they do nonetheless.
It can be easily bypassed though if the base images for the tilemap are added while the packages are uninstalled the problem is fixed.
Do not change the import settings while the packages are installed this will break it again and you will need to remove the package and replace the images again.