Firefox 128 snap Telemetry privacy problem?

I have all telemetry disabled in Firefox settings.

Settings > Firefox Data Collection and Use: all unchecked.

Still I see JS running on searchpages (Google, Bing) with binding events to the input field, like:

sync event => {
  let start = Cu.now();
  if (condition(event)) {
    callback({
      action,
      target
    });
  }
  ChromeUtils.addProfilerMarker(
    "SearchSERPTelemetryChild._eventCallback",
    start,
    "Call cached function before callback."
  );
}

Seems to be a part of Firefox Telemetry, but I don’t want that running, and of course it should not run when all telemetry is disabled.

Firefox 128 Ubuntu 22.04

What is going on? How do I disable this code?

BTW I don’t see this with Firefox Beta 129 (deb)

Strange,

I don’t see it when I create another profile, so somehow my profile seems polluted.

Can remember I once (2019) enabled Mozilla Beta studies and installed this extension to fix an add-on issue.

Can’t think of anything else for the moment.

Anyone with tips how to debug this issue?

This forum isn’t very active and postings here often don’t get useful responses.

I suggest trying the more active discussion rooms on the Matrix. https://wiki.mozilla.org/Matrix

I’d start with the Firefox Desktop Community room.