3.7.0 several issues when activated

With activated 3.7.0 release in Maintenance mode I’ve several issues with previewing pages/posts when already logged in as admin. Normally there shouldn’t be shown the maintenance site to an already logged in administrator. Nevertheless it happens, and after login again in the newly opened preview-browser-tab I don’t see the preview of the pages/posts I asked for. Always page “Home” will be displayed, not the one I wanted to preview. Switching Maintenance mode from on to off, doesn’t change anything, I furthermore get the Maintenance site and have to login as admin for the previews. Any idea what’s going on here?
PS: Deactiving and activating the 3.7.0 doesn’t change anything. So I tried for testing purposes another maintenance plugin, everything worked well as expected. But I wanna stay at 3.7., it worked fine for me in the past.