I have noticed that when I use Google Maps instead of Bing Maps that it does not display properly. When I zoom in/out it sometimes goes to a black screen, making it very hard to use.
It is possible that this issue has been corrected in a recent update as I am not able to replicate it. You may want to update or uninstall and reinstall your copy of Microsoft Edge Insider build.
@v-gapart Concur, it now seems to work correctly.