I don't have the solution, but to relay a weird experience with the same...
I imported an object from 3D warehouse and got similar results.
I copied the object into a second PLN file and the image map mysteriously
corrected itself. I haven't tried to replicate the process.
What happens if you convert the object to a morph?
Marc Corney, Architect
Red Canoe Architecture, P. A.
Mac OS 10.15.7 (Catalina) //// Mac OS 14.5 (Sonoma)
Processor: 3.6 GHz 8-Core Intel Core i9 //// Apple M2 Max
Memory: 48 GB 2667 MHz DDR4 //// 32 GB
Graphics: Radeon Pro 580X 8GB //// 12C CPU, 30C GPU
ArchiCAD 25 (5010 USA Full) //// ArchiCAD 27 (4030 USA Full)