I apologize in advance if I'm adding 'noise' to this conversation and that what I'm seeing isn't related. I haven't been able to consistently repro this issue, but it did occur again for me this morning. My AV was standing idle and I wasn't actively doing anything in the viewer, when many elements of the scene flashed and appeared to refresh. After that moment, when my AV faced particular directions, some textures exhibit a similar condition as Kathrine reports. I have captured images from just a few degrees of rotation in my AV. They are:
https://ibb.co/4Y7hx5g and
https://ibb.co/9bxmt7j. Something I hadn't noticed before is how the name tags also become corrupt in addition to my wings, the clouds and the skylight windows of the pavilions. It seems, for me, only textures with transparency are affected. I'm including my log, but it doesn't really contain anything of note at the time the scene flashed/refresh (~12:09). If I continue to rotate my AV, the textures also appear to rotate until I pass a certain point at which they return to normal for the rest of the 360 degrees of the view. They are corrupt only for a narrow slice of the full view. TPing to a new location, seems to reset everything.