Issue with Tabs

I have been cutting out shapes for a while now and every time the z axis move to the safe height it creates a bump/dimple on the side of the part. I can tell something is wrong because the router leaves a nice burn mark all the way up and back down. Then it is off very slightly on the last pass.
What could be the issue.
I am cutting .47 in ply with .1 z movement @ 40/50/60 IPM
tried 1/8 carbide router and 1/4 carbide router bits.

The cuts look great until the tabs get started.
Is this a normal occurrence for people that use tabs?

I’m having a minor but similar problem. I made the assumption that in my case it was either the wear and tear on my 20+ year old rotozip sc101 which might have caused some of its loss in tolerances or slight wobble in my cheap Chinese mill bits. I’m curious for any other explanations.

Like Richard hinted at, I believe this can be caused by runout of your spindle, or your Z-Axis not being square.
The Z-Axis is not running 100% square to your material, so the lower it goes, this offset gets worse and worse, hence causing the bump.

Can you do a test cut of some thick 1" material, and see if your cut is perfectly square to the surface?

However maybe more likely, a loose Z-axis will cause this undesired movement of the bit while it is moving. Instead of moving only up and down, its moves side to side as well while the tabs are being cut.

I have never been able to get perfect profiles around the tabs and my machine is pretty rigid. The solution for me was to use “3D tabs” that are sloped on the sides instead of square. These are sometimes called “ramps” or ramped tabs. They descrease the vertical force and flex and are also easier to remove after the fact. No more scarring on the sides.

I have not used Easel but I believe it is capable of producing these tabs.

I think Fusion 360 has the same option, and calls them triangular tabs.