quite the n00b concerning Blender and I ran into my first issue concerning the texture of a UV Map pointing in the wrong direction of a mirrored object.
To give context I attached a screenshot: Green marked side "normal" shows the texture how it should be. Red marked side "darkened" shows stair rows darkened (pointing inside). When I view the object from the back the correct texture (which would be the green one) is visible.
Methods I tried to create the mirrored object, knowing this could cause issues:
Method 1.1: Mirror object by short cut Method 1.2: Mirror object using the Mirror modifier, then apply it and make a selection with key "p" from the mirrored part
Resulted in the same behavior (UV Map texture pointing in the wrong direction)
Attempts to fix it:
Apply scale after mirroring the object
Checking if the normals are correct: Method 2.1 Recalculating the normals Method 2.2 See if any normals are flipped (they are fine)
Trying to mirror the UV map (UV -> mirror) with "X Axis" and "Y Axis"
I tried to find a solution here and elsewhere and couldn't find anything related to this issue. If the information I provided isn't enough, please let me know what else I can provide.
Disclaimer: Unfortunately a moderator deleted my post, as a response to the possible solution provided by Crantisz. I don't have enough reputation to comment on his post so I had to go through this route: I have tried pressing shift + n, after applying scale, to recalculate the normals numerous times. Unfortunately this didn't solve the issue.
Also: I tried the solutions suggested in this post with no success: