I get it sometimes with my elevation background material.. I can't say how to fix it for good but for me erasing the face and doing [Ctrl]+[Z] works to make it render correctly.. at least till next time I open the file.. Sometimes it stays correct .. sometimes it doesn't.. It happens with textures which are quite a lot scaled up.. I'm guessing size of Your microwave texture is 'inch x inch' and it is scaled to fit natural size of microwave.. You can make texture size matching the real size of device but then You will have to reposition textures on all the faces..
and here after deleting a whole group (blue) containing this face and undoing it.
So I guess you can delete Your component and undo it.. But that is work around not fix.. Though I know no better. This gradient ground texture is actually scaled down from original 40m x 20m - so about 3 times. I tried texturing on both sides, this is on one (front) side.. all the same.. actually the sky texture is scaled down to about half.. Never had a problem with this one.. and they are in the same group, tag etc.. No clue why is it always this one making a trouble..
Hey, Tomasz, thanks for replying!
It was a project I was working on only for my portfolio, but I got some jobs so I didn't have time to mess with it, but now I do.
I was going for your solution, but instead of deleting the whole component, I was going for the very face that had the texture on. However, that made me realize that the texture was applied to the whole component (somehow I missed that). So I took the texture out of it and then filled only the front face I needed and it worked.
Thanks, once again! I'll also keep in mind the delete and CTRL+Z work around you taught me!