OK, I thought this was a one off glitch, but it seems to be an intermittent issue, happening several times during a session. It applies to grids and form applications:
1- In the IDE when I have a form open for design in the IDE it displays OK
2- At some point switching between tabbed pages and back the page displays blank. I
3- The blank page tab will not close
4- to restore I need to close and re-open the browser
This applies to Chromium and Firefox on a Windows 10 client.