I usually work out with a HRM-TRI connected to my FR945 with software 2.80.
What I've noticed is that often when I'm done working out (running or cycling) and take off my HRM-TRI the watch suddenly shows an insanely high OHR (like above 240 when my max workout HR is only 170 or so). It stays like this until I reboot my watch.
I've done a hard reset already but that didn't help, today I again had a 245 OHR after spinning.