Pixel 4 no longer connects to Ubuntu machine

I have a Google Pixel 4 phone. It used to be that I connect it via USB to my machine running Ubuntu 20.04.2 LTS and on the phone check File transfer/Android Auto and then it would be listed in a Dolphin window. Then one day, this just stopped i.e. nothing appears in the Dolphin window.

I don’t recall changing anything but I must have. How do I get this back?

Edit:
Tried different USB ports and cable. No change.
lsusb does not show the phone
Developer Options > USB Debugging is on
Android Version 11


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Author Of this post: Al Lelopath
Title Of post: Pixel 4 no longer connects to Ubuntu machine
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