No HBO/Showtime on Xfinity Stream

I need some assistance solving a problem I've caused for myself.

On Sunday, I was looking for a way to reduce my bill, and I thought I'd try subscribing to HBO and Showtime directly, via their apps, rather than via Comcast.  I cancelled my Comcast subscriptions to both channels at that time.

By Monday(!), I'd realized that the direct subscriptions were a dealbreaker since I couldn't DVR shows (using my TiVo w/ Comcast CableCard.)  I cancelled the direct subscriptions, and re-subscribed to both via Comcast.

All HBO and Showtime channels were immediately available again via the TiVo w/ CableCard, as expected.  Via the Xfinity Stream app, which I use for OnDemand, I'm still unable to watch HBO or Showtime.  I've tried Xfinity Stream on Roku, iPad, and in a web browser.  When I choose an HBO or Showtime show, it asks me to subscribe... which I'm unable to do, since I've already re-subscribed.

So, yeah, I really messed things up!  I'm hoping someone can point me at a fix.  Thank you in advance!