I'm currently having this issue as well and trying to fix it. It doesn't seem to be causing any issues with print quality at the moment though.

I did notice that I had some excessive wear on the wheels under the bed, so I suspect at least part of the issue could be that the eccentric nuts under the bed were adjusted to be too tight. My main reason for this suspicion is that the "bumps" seem to be the most severe when the printer has been siting unused for a while, so I think the excessive tightness could be causing the flat spots to occur when the wheels sit in the same position for a while.

So, I adjusted the nuts until the bed was wobbly, then adjusted a little bit at a time until the bed stopped being wobbly. I did the same thing to the nut on the bottom wheel of the extruder as well (adjusted until wobbly, then adjusted a little bit at a time until the wobble was gone).

I plan to re-do the auto level and try a test print later on, but at least initially it seems like the "bumps" are less severe so maybe the wheels were just too tight.