Several Display Problems

I am having several issues with display graphics. In the morning some roads are missing. Track is overlayed with PBR stuff (landslide effect) and the little blue rotating circle appears on main menus. Also, sections of track are missing as are portions of some roads. Yes, I know that I should look for patterns, note them, and then document a trouble report. That takes TIME. At my age it is not a limitless commodity. Is that little blue rotating circle on the menus a clue? I have allowed the program to run overnight and also performed both database sorts.

I am using the Coal Country route as a base with two other routes merged to it. Mixture of older and PBR textures.

The suppressed by PBR splines are the most predominant event., followed by road splines vanishing.

PC is new with an i7 CPU, 16gb memory. Video RTX 3070, 8gb memory. Temperatures well below TjMax.
There is undoubtedly no "magic setting" so any strategies will be welcomed.

The problem of the PBR textures overlaying the track is often (most likely) caused by having your Shader Quality set to Ultra. If that is the case change it to Standard. The setting is in Trainz Settings --> Performance. A restart of Trainz will be needed after making the change.