Saturn 4 Ultra Significant Lines on Flat Surfaces

Been printing successfully and with great results for about 5 months now with the Saturn 4 Ultra - previous 2 years with a Saturn 2. NFEP (Elegoo brand) changed 1 month ago and produced crisp prints. Latest firmware. Printed at 25 degrees C in a heated enclosure not the internal Elegoo heater, 2.2 seconds per layer at .05 layer height (lychee - no issues with adhesion or formation of supports). I have been printing well until recently. These are with AA (and without) slow and fast print mode. Screen tests were good, and self check is good. I have tightened the Z axis motor (two screws that attach to the body) and added more grease to the screw and rails.

Help would be much appreciated.