How can I fix editing a Tilemap as a Prefab?

[Jedyte28351]

In my 2D game I generate a level by having a script laying out Rooms at random. Each Room is a Prefab, consisting of 2 (or more) Tilemaps.

When trying to edit these Prefabs in Prefab mode however, there seems to be a graphical glitch, and as a result I cannot edit the Tilemaps. In below screenshot the Tilemap consists of 40 tiles, but I only see this:

Anyone knows what is going on?
Thank you

[Jedyte28351]

Since then I found a workaround. It’s been almost year, so I don’t fully remember what it was that did the trick.

I structure my prefabs now like this:

As you can see there is a root object. This contains the Grid component. (I think that was the trick that did it.)

Underneath I have child objects with Tilemap components.