• June 28, 2022: Firefox 102.0, See All New Features, Updates and Fixes
  Firefox now mitigates query parameter tracking when navigating sites if you have enabled strict mode for Enhanced Tracking Protection.
• June 28, 2022: New Firefox privacy feature strips URLs of tracking parameters
  To enable Query Parameter Stripping, go into the Firefox Settings, click on Privacy & Security, and then change 'Enhanced Tracking Protection' to 'Strict.'

It's a privacy feature. You can disable if you want

That looks to me more like it's Amazon removing them, assuming that's happening when you load the page. They probably remove them so that people don't copy and share affiliated links so that they don't have to pay out more to their affiliates program.