This can be caused by gantry misalignment/warping, or not registering the bed mesh properly. Also, maybe the bed is warped in some way that was in the middle of the test points, so maybe a finer mesh could fix this.

That looks like just AB and no L

ABL doesn’t automatically measure the right distance to your bed. It has no idea where your nozzle is. Your nozzle is somewhere between the sensor and the bed, but the sensor doesn’t know. You have to calibrate that. If your nozzle changes (swapped, comes loose) or your bed changes (moved, replaced, damaged) then you recalibrate.

There should be an option to micro step your Z. I have a Sovol SV06+. I run the ABL routine, then print a 1 layer square. If that’s too close or too far, I adjust. My options are 0.05mm and 0.01mm steps. Adjust, reprint. Adjust reprint. See the images here, for what it should look like. https://help.prusa3d.com/article/first-layer-calibration-i3_112364

Given that this doesn’t look uniform, it looks ‘random’ – you need to check that your hot end is actually secure against the X carriage.

If this were uniform, like it faded out from a low spot - I’d tell you there was debris under the bed, or a mis-measure on the probe (it happens, they aren’t perfect)

ABL isn’t a solution for leveling problems. ABL is a ‘lazy’ test for an already-well-tuned printer. If you’re having leveling issues, an ABL won’t work right because it assumes everything is working perfectly to begin with.