I was able to reset Affinity Photo as you requested. Issue is still there. I took couple of screen captures after the reset, see attachments. I also closed the application and launched Photo again, no help.
Right side of the dropdown menu all sub-menus are on the left side. Left side of the dropdown menu all sub-menus are on the right side. Same session. I haven't never experienced the same problem before and been using Affinity Photo already for sometime.
I haven't done any changes on Windows settings. All the other applications are showing dropdown sub-menus right side of the menu. Not switching right-left-right etc.