It looks to me like the filament is getting bound up in the side of the spool and getting trapped, reducing extrusion flow until it pops out and starts feeding again. I had an almost exact issue that was driving me crazy.
Then I started watching the spools for an entire print and I caught it binding in the edge, holding a few seconds and then popping out. I printed the little guides that people use on the end of a short piece of tubing to help prevent the binds and the issues went away.
Banding at the same height indicates that something changed on that layer, in the slicer preview look at the Speed, Flow, Layer and Fan speed graphics and see if you can identify changes on any of those that coincide with your banding zones
If you change nozzles or other vital hardware it is recommended to let the machine do a full calibration.
Nozzles can wear out for example and the calibration addresses vital variables.
I even do it after firmware updates as sometimes even those mess up settings.
Whats inside model, sometimes walls get shrinkage/blown out with infill or ledges.