case USB_ST_SETUP:
 		/*
-		 * Check if the recording stream can be used as a
-		 * source of jitter information to save some
-		 * isochronous bandwidth:
+		 * Submit the transfer even when the recording stream
+		 * provides the jitter information, so that the feedback
+		 * rate keeps being sampled for diagnostic purposes.
 		 */
-		if (ch->priv_sc->sc_rec_chan[i].num_alt != 0 &&
-		    uaudio_debug == 0)
-			break;
 		usbd_xfer_set_frames(xfer, 1);
 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_framelen(xfer));
 		usbd_transfer_submit(xfer);
@@ -2884,12 +2950,33 @@ uaudio_chan_start(struct uaudio_chan *ch)
 		if (uaudio_chan_need_both(
 		    &sc->sc_play_chan[i],
 		    &sc->sc_rec_chan[i])) {
+			struct uaudio_chan *ch_play = &sc->sc_play_chan[i];
+			struct uaudio_chan *ch_rec = &sc->sc_rec_chan[i];
+			uint8_t rec_alt;
+
+			/*
+			 * The recording channel is only being started as a
+			 * source of jitter information for the playback
+			 * stream.  Align its nominal rate with the
+			 * playback rate so that (a) it does not reprogram
+			 * a sample clock shared with the playback path to
+			 * a conflicting rate, and (b) its expected frame
+			 * sizes match what the device actually produces,
+			 * keeping the derived jitter information valid.
+			 * The USB explore lock is held here, which also
+			 * serializes against uaudio_chan_set_param_speed().
+			 */
+			if (uaudio_chan_match_rate(ch_rec,
+			    ch_play->usb_alt[ch_play->set_alt].sample_rate,
+			    &rec_alt))
+				ch_rec->set_alt = rec_alt;
+
 			/*
 			 * Start both endpoints because of need for
 			 * jitter information:
 			 */
-			uaudio_chan_reconfigure(&sc->sc_rec_chan[i], CHAN_OP_START);
-			uaudio_chan_reconfigure(&sc->sc_play_chan[i], CHAN_OP_START);
+			uaudio_chan_reconfigure(ch_rec, CHAN_OP_START);
+			uaudio_chan_reconfigure(ch_play, CHAN_OP_START);
 		} else {
 			uaudio_chan_reconfigure(ch, CHAN_OP_START);
 		}