Weirdest record defect?

A couple weeks ago I went to a small venue to see a little-known artist Mary Timony. I discovered her when her latest album "Untame the Tiger" was featured on Qobuz under "New Releases". I picked up a copy of the record at the merch table after the show (great show btw). So here is why I am posting-throughout both sides of the record at fairly uniform 90 second intervals there is a loud bass bump/thump. Loud enough to be concerning as to my woofers. The record is perfectly flat and there are no visible defects. There is no discernible static problem and static would not cause a low frequency thump.

The label is Merge records. Any ideas as to the cause? I have never encountered this before.