Yet another Ergdata - Apple Watch - PM5 question

I know that versions of this same question have been asked numerous times, and believe me: I've searched this and other forums. I think I've tried all the fixes suggested.

I last rowed on 5/22 and the connection with my Watch, iPhone and PM5 was seamless, as usual. I woke up the PM5, launched Ergdata on my phone, it connected to the PM5 right away, and I tapped JUST ROW. Ergdata on watch started right up displaying heartrate which as always takes a few seconds to read. HR appears on my phone and on the PM5. That's how it's supposed to go.

Yesterday, it did not. Everything went as usual except that Ergdata on my watch appeared to not launch. Except it did: after while I saw that it launched to the Ready to Workout? screen for a fraction of a second, then reverted to the watch face. Ergdata is still running on Watch at this point, in the background, still on the Ready to Workout screen. I guess that counts as the app crashing?

I tried all the usual fixes: toggle Bluetooth off/on, toggle Ergdata permissions in Health, restart phone, restart watch, update iOS to 26.5, update Ergdata app to 2.13.6, delete Ergdata app from Watch & Reinstall, remove/replace battery from PM5 to reboot (forgot about 4 button press to shut it down)...I think that's all. Did I miss something?

Firmware on the PM5 262.067. It's a Model C Rower. I always update firmware when prompted. Last time though I seem to remember getting an error message? That is a clue maybe.

I'm going to try to get in touch with Concept2 tomorrow. Thanks in advance.