Mac OS Big Sir and the Dock

Hi all.
I recently upgraded to big sir on my MacBookk air in preparation for eventually upgrading my daily driver.
Everything is fine apart from I am having an issue with the dock. I am unable to view the menu for any icons, and even if I do, and try to remove it, the icon does not go.
I've tried VO shift M, and using the actions menu's "show menu" option but nothing worse. Sometimes it jumps me back to where I was before I moved to the dock, or it gets me stuck in a dock application with no windows.
I thought it could be something like if the dock was being automatically hidden, but that option is not checked.
Has anyone else had this issue or know what is going on? Mac OS big sir 11.1 running on a 2013 Macbook air.
Thanks.