I suspect you're at work and can't log into TenForums. Or maybe that should be Work Sux!
I've copied all the pertinent information from everything we've tried to get you receiving new Insider Builds and will recap everything so far, and then list things we haven't tried so far.
Since a new Insider Build has dropped, and this thread will most likely be closed, I will start a new thread in the Windows Insider Group titled:
Cannot Get Insider Builds after RTM Build 10240
With this new thread, we'll be able to talk exclusively about your issue.
Wait! Before you do that!
I was actually enjoying Canadian Thanksgiving with my family, but I'm back home now, and as soon as I saw the Insider Hub notification of a new build, I checked Windows Update. BAM! I have no idea why I never got a previous build, but looks like I won't have to do a reinstall or dual boot for anything, since both machines got it!
I appreciate the help you guys, and sorry I couldn't read all of your responses. See y'all in whatever new thread gets made!
I'm still laughing; we worked so hard on this, and I feel like something we/you did finally broke through the dam! So we can close out this thread with our heads held high!