I suspect the issue is you have a broken spring or failed strut. I included the process on how to replace this but that is what would make sense in this case. If you are not hitting bumps then it is quiet but as soon as you hit something that strut is bottoming out or spring is popping.
When you hit the bump does it sound like a thud or metallic sounding?
If you can get a recording of you hitting speed bump so we can hear the noise, that will help as well.
I included the process below on how to replace this as I suspect that is the issue.
Let us know thanks.
Images (Click to enlarge)
Monday, January 18th, 2021 AT 2:52 PM