Cyclic Banding on scan

Good Morning…Eleksmaker A3 2.5 watt…GRBL 1.1e…Mana SE Ver 3.1 controller…while scanning a rectangle 10 x 20 mm at 250 DPI @ 17% and 20% I noticed some cyclic banding…Replaced belts…aligned machine…focused beam…cleaned tracks…free movement x and y… see attached screen shot and photos of scans any thoughts…Thanks in advance…