does it happen during a clean boot?
Try a clean boot and see if it changes anything - make sure to read instructions and make sure NOT to disable any microsoft services or windows won't load right -
https://support.microsoft.com/en-au/help/929135/how-to-perform-a-clean-boot-in-windows
if clean boot fixes it, it shows its likely a startup program. You should, over a number of startups. restart the programs you stopped to isolate the one that is to blame.
will tell us if its part of windows or one of your startup apps.
I have seen that before myself and fixed it. This is the chrome answer -
https://winaero.com/blog/how-to-dismiss-windows-10-media-volume-control-pop-up/ but its possible one of your other apps is doing the same.
there is no central place in windows to control this feature, its why you find answers around for spotify and chrome.
Edge uses chromium (or is going to, its confusing) and as such the advice for chrome may apply to Edge now... that feature was actually added by MIcrosoft -
https://www.windowslatest.com/2019/06/18/microsoft-edge-gets-media-overlay-support-on-windows-10/
I assume this will be rolled out with 2004 -
https://support.microsoft.com/en-au/help/4501095/download-the-new-microsoft-edge-based-on-chromium