Materials being renamed

Hadn’t noticed it before but recently Materials are being renamed from their originals to mat001, mat002, etc. For example the material thumbnail was originally named Sketchy Brick Herringbone. Now it’s mat015. Perhaps a plugin?

Thank you,
theVonZipper

Are you running some sort of rendering application like Vray?

Which version of SketchUp? Your profile here says 2018 but on Sketchucation is says 2019.