This looks most likely like an issue with async texture loading. Could you share this sketcup file with us?
Alternatively you could try to disable async texture loading to see if it will help:
1. Create text file ~/Library/Application Support/Enscape/userPre.cfg
2. Add the following line to that file:
3. Close SketchUp, open it, start Enscape
If blue anomaly is gone - this is async texture loading bug. In such case we definitely would be glad to have sketchup file to reproduce and fix it.
Disabled async load will lead to longer loading times.