[OPEN] Can’t delete/select walls or add wallpaper

1. Is your issue affecting just walls, just wallpapers or both? Both. It's like the wall isn't even there. I can see it but can't interact with it in any way.
2. Which specific lots is this happening on? Could you list them? For sure Granite Falls 50x50. I don't remember the other ones, but they were residential lots in regular worlds.
3. When it happens is there anything unusual about the appearance of the lot in the map view? Is it a slightly different colour to the rest of the lots or just looks a bit off? No difference.
4. Can you remember what you were specifically doing before it happened? Was there a sim on the lot or were you just building? Had you just flicked from live mode into build mode? Had you been using a specific build tool at the time? I was building. I didn't enter live mode and there wasn't a sim on the lot. I was just in the middle of placing and rearranging objects.
5. Are you using any Mods that may alter the behaviour of the Maxis build tools or add additional functionality? no.

1. Can't add wallpaper or delete walls. I can select the room and move it for some reason.  
2. I can't remember which ones, I think I had it on multiple lots
3. Not that I noticed, will keep an eye out if it happens next time
4. Can't remember. Will edit this if it happens again and I'll try to pay close attention 
5. No mods or cc at all, never have

Not very much of help yet, sorry.  

It's affecting all wall painting options including wallpaper, tiles, etc.
I'm having this problem on 20 culpepper house
Doesn't appear any different on the map, looks normal
I had just loaded into my save file and wanted to update my childs bedroom from toddler to child
I wasn't using any mods that affected building at the time, and I removed all mods anyway to see if it was causing a problem

just to note, it's only affecting certain portions of the apartment, not the apartment as a whole, im also having problem laying the floor down with it saying the same thing "cannot place due to fixed object"

I'm having this issue (walls are unselectable, unpaintable)when loading fresh into the game, I have zero expansions, packs or mods (never have) and it seems it only began happening after the house I'm working on got fairly large and complicated. I'm not sure if I have placed "too many"walls or what. There are also quite a lot of shrubs on my lot. But it seems to me the game should know how to manage these resources and warn us or prevent us from placing too many objects.

Another key that this is happening is that windows can be placed but ONLY at the very lowest point, trying to move them up the wall will instead move them through the wall.

I'm playing on one of the 40x30 lots in Newcrest, Avarice Acres, I have never activated or used cheats and again I have 0 expansions (I'm a cheapskate, what can I say?) and have never used mods.

Attached is a picture of my house (for scale) with the issue occurring

I am on the latest version of win 10, latest graphics drivers and latest version of the Sims.

I have a Ryzen 5 1600X, 16GB RAM, nVidia GTX 2060

• Is your issue affecting just walls, just wallpapers or both? :Both. Occasionally glitches out and I can't select walls or use wallpaper like they just don't exist
• Which specific lots is this happening on? Could you list them?: it's random and not constant
• When it happens is there anything unusual about the appearance of the lot in the map view? Is it a slightly different colour to the rest of the lots or just looks a bit off?: Nothing unusual
• Can you remember what you were specifically doing before it happened? Was there a sim on the lot or were you just building? Had you just flicked from live mode into build mode? Had you been using a specific build tool at the time?: I was changing fences and colors I think. Then I tried to use eye dropper tool on a wallpaper, and it acted like there was nothing there. I was only building on an empty lot I wasn't using any household, but it happened previously when i was building on an inhabited lot too.
• Are you using any Mods that may alter the behaviour of the Maxis build tools or add additional functionality? I am using a beds mod to give them all the same energy, and a fridge/stove mod for making all consumable the same quality.