Well, they all came back for a day; non-PBS 20, 50; PBS: 32, 26, 62 all good. Got a couple of shows on DVR.
Now, are still getting 20 & 26 &32 OK, but 50 & 62 back to the "we know, don't call" slate.
Strange symptoms, still assume they've just lost the local-to-dish feed.