I am new to vinyl but I had a similar issue with a couple of Radiohead issues from Capitol records. There were others who had experiences similar to mine and a friend experienced in vinyl told me it was most likely (non-fill???). I think this is condition where the vinyl does not fill all of the grooves of the stamper and leaves a "pocket" in the LP groove that causes distortion particularly in louder passages.
Jimbojrjb, your experience sounds very similar to this.
Jimbojrjb, your experience sounds very similar to this.