Make sure they are not overlapping or have gaps in between eachother, if that doesn’t fix it try offsetting the texture a bit.
There are no overlaps or gaps.etc. All 4 textures have the same offsetting but I will try that.
To add, I had also noticed this yesterday but after a while it disappeared and they were able to overlap over each other without any lines. It came back today
I had this problem. If you zoom up to it the black lines will disappear if you zoom out it will reappear it would be nice if Roblox could fix this. I think it happens to most textures that are high res lets hope Roblox will make it so we can use higher-res textures in the future.
I tried using surface apperance that is in beta you could use that since there are no black outlines in that
Looks like your parts are slightly maligned/overlapping, just tested it on studio
4 regular parts perfectly aligned with each other
https://gyazo.com/06a14a063c4a995886cb6ebba862436a
https://gyazo.com/849e744361e1868cc052f95b3e20ed2b
look fine when they are a good distance away. Did you try to hand-align them?
I’d recommend using the F3X plugin and using the snap function to automatically align parts (Hold R over a part corner and then snap it to another)
Go close to the those black lines do they disappear. They are just render bug. Try to use 4k