is it toothed idlers?

I went through all the settings possible one by one that could fix "ringing", nothing worked(over 1 year so I have tried a lot of things) this is why I am sure it is something physical now. I noticed this irregular patterns on all my printers vCore 3.0/3.1, prusa MK3S+ and an ender 3 v2, whether it is klipper or marlin with any speed/accel it still appear and I have spent a lot of time and money trying to figure out what is wrong for my vCore 3.1 500mm² I noticed that my y stepper shaft was slightly bent and for sure thought that was the problem so I swapped it with one of the more straight shaft z motor ( got hit in the face by the bed, which saved it lol, careful when unscrewing things...) and for sure obviously it is better but it is still here and it honestly look like the toothed pattern of the idler now that I think about it ( the belt sit perfectly still on the both idler on any movement on my 500mm² bed) I went from all version of EVA up until 3, ditch all that bought everything in freaking aluminum( all corner, bed bracket,light x beam...) with the VZbot aluminum head, vzExtrudor, goliath. Same god damn problem. I am going crazy? I am to perfectionist? like what is going on, been trying to fix this for over 1year