Uh oh :( Might be a Safari problem.
<rdar://problem/30022309>
(In reply to comment #0) > Uh oh :( Might be a Safari problem. Repro in MiniBrowser, so probably not.
The key combinations were changed from Command-1..9 to Command-Option-1..9 in https://bugs.webkit.org/show_bug.cgi?id=159487, to avoid conflicts with Safari.