Same. Back button not working, although the mouse's back button works on Settings, so it is not a big issue for me.
I also have a problem where the taskbar disappears over the Start button if I choose to use the OS default in WB.
BTW, this is on a clean install of both WB and Windows 10 1903; I was trying and failing to fix a problem with USB 3.0 flash drives caught in a connect/disconnect loop (MS is at fault on that).