White lines appear on some edges of a model I made in Blender

I’m getting strange seams of white noise/lines on some edges of my model from Blender. I have no idea why this is happening, since no such white lines can be seen in Blender. I made sure there are no double vertex involved on these edges. Can someone help? Does this have anything to do with lightmaps?

Above is one of the many white line seams in Unreal Engine

Above here is the same window seen as is in Blender


More cases of the strange lines on my model.

Example of the face that borders one of the white lines, and its texture UV location, in case it’s relevant

I am at a loss here.

I am a newbie, but I noticed that recalculating the normals within the uefn modeler solves problems sometimes.

i will check that out, though I’d prefer if I could somehow prepare the model to avoid such an issue in the first place. My plans are to sell this model as an asset, if it creates so many issues upon importing into Unreal, then its quality as an asset wouldn’t be great.

I’ve had no luck so far. Anyone?

Okay it’s doing even worse things. It’s distorting my texture even though it’s the same file and this shouldn’t happen??

I am about to give up