These are caused by the nodes being too close together in a heavily fractalised polygon. Notice how they occur on the fractalised parts of the object rather than the simple straight line sections.

Undo or delete the new wall tracing and use the keyboard command SIMPLIFY, set a distance of about 0.25 (if that is a 5ft snap grid I can see), on the floor polygon. What this will do is remove any node that is only 0.25 feet or less in distance away from it's neighbour. Then either trace the wall shape again, or copy that polygon onto the WALLS sheet and hide the FLOORS sheet to change the properties on the WALLS sheet to create the new wall.

We are working hard on it. However, since my part in the whole thing is creating new assets for just a bit of it I can't really throw much light on anything else.

The wall of links that Jim mentioned above is here:

https://forum.profantasy.com/discussion/10366/cartographers-annual-all-the-issues-linked-in-one-place

That's a good idea too.

Most CC3 dungeon styles are top view orthographic, so you would only ever see the wall and not any part of the face of it, so it's quite rare to get such symbols.

Yes, I remember there being something myself but I can't find it now either. We must both be using the same 'wrong' search words.

But never mind - I can possibly help you here.

Make a new sheet immediately above the one with the repetition issue (under it in the sheet listing because the sheet listing is upside down to most people's way of thinking).

Either:

1. use one of the semi transparent fills (denoted by having a 'T' in the fill name in DD3) in patches on that sheet, or
2. add an Edge Fade Inner sheet effect to the new sheet, and then draw patches of similar textures on that. When you refresh the drawing the EFI will blend the edges into the old sheet.

It's more effective to use similar textures rather than the same one. For example if you have several shades of grass use one of the other shades of grass to patch the original grass.

It can take a little practice to get the second method to work correctly, but I've found it more effective than the first one.

...

EDIT: It is also worth remembering that repetition becomes far less obvious when there are more objects in the map, so if you are staring at just the background with nothing else at the beginning of a map you will inevitably see the pattern. It might be worth finishing the map before you decide to go through the process of patching.