I have been trying to make a tilemap while using the new LWRP 2D renderer. I first installed the LWRP 6.7.1, package, then upgraded my project to the 2D renderer and only afterwards I have added the Tilemap Editor.
When i tried adding tiles to a new tile palette, the tiles won't render in the tile palette.
If i try to paint with them, though, they will appear in the scene.

To reproduce this:
- download this project
- select any of the tiles in the project
- try to add them to a tile palette
- notice that they don't appear in the tile palette
- if you can pin-point where the tiles are and select them with the brush tool, you will notice that you can paint with them afterwards, thought they are a bit small

Only able to reproduce this in projects where I use the LWRP 2D Render pipeline - in the legacy renderer, this works well.
Reproducible with both 2019.2.0b6 and 2-019.3.0a6