It’s hard to say what the underlying problem may be from just a few screenshots.
There are lots of dialects around of the Gerber format (which started 40+ years ago) and it seems quite common that PCB manufacturers stick to old buggy software because it’s “working” in their machines.
It is a bit suspicious that apparently two different manufacturers see the same circles, but it does not mean much because they may very well use the same buggy software. It does appear though that they have a different amount of circles and on different layers.
Some time ago there was a thread here about a bug with circles in the gerber software of JLCpcb (especially the online viewer). It was about radiusses in pads not being rendered correctly, and even someone from JLC participated in that thread to get to a solution.
KiCad’s gerber files are generally quite good but sometimes uses newer features of the Gerber format that not all manufacturers can handle properly.
I have a vague memory that it sometimes helps to uncheck Pcbnew / File / Plot / Plot format: Gerber / Gerber Options / [ ] Use extended X2 format to gain more compatibility with PCB fab’s that use older or buggy software.
What is at the center point of all those concentric circles?
Are all those circles concentric with a round PCB outline?
Do your current Gerber files view properly in the Ucamco Reference Gerber Viewer?