Stuck in monthly enterprise channel

Trying to get the Beta Channel installed.  Policy seems to be set.  However, I seem stuck in the Enterprise Channel.  I've done a full uninstall/reinstall cycle.  This is my personal PC but I previously added my work email to Outlook/Windows and I fear that has me stuck and I can't find the policy/registry to clear it.  I think 16501 is from May.

Please help....