Sorry for the late reply. I’ve been having a few days off.
You can check two things.
Firstly, as shown in the image below, you can check if the dummy material has texture and the scaling is too large, which will cause the problem as described.
Secondly, click on this
(sorry not in english… but you can find the corresponding items in your D5 Render). You should check the values of Horizontal Scaling and Vertical Scaling. These should actually be directly related to the material texture scaling in revit.
When the dummy material has no texture, or no standalone uv is used, or all these values seem sufficiently normal, you can upload your project file (you don’t have to upload the complete project you are working on if you can’t, though it is better for the debugging purpose; you can in this case delete everything else except for the element with overscaled uv), or email it to me ( firstname.lastname@example.org ), and I’ll fix this as soon as possible.