right clicking onto audio channels freezes timeline and I can't select channels

Hi I've just started a new project and when I click onto the audio channels on the time line and right click audio channels it freezes the timeline and I can't proceed.  If I press escape I can continue to work on the timeline but I can't adjust the audio channels.  I have closed adobe and reopened.  I have also tried opening a couple of other recent premier pro projects and the same thing happens when I try to adjust the audio channels thing in those projects.  This wasn't happening yesterday.  I have recently imported some new footage into this new project from the same card/camera as before which didn't have previous problems.  I have also imported some video from my IPHONE 13 pro.  When I did this I did get a message about windows not having a certain codec to read the file and needing to buy something.  I can't quite remember the codec, but I proceeded anyway and the clip played.  Not sure if this has affected the audio in some way?   Can anyone help.  I can't proceed with my project.  Thanks

Details:

Premier Pro V.2023

64 bit operating system and 64 bit processor

Windows 10 22H2

OS build 19045.3448