Garmin 540, update 28.34

Is the HRM dropping bluetooth wise, or does the HRM module have no data? They are different things. I had a faulty/worn out HRM strap that would sometimes work, then start giving reading/no read/reading/no reading, and the reading was wrong. Replaced the strap, and it works perfectly again. YMMV.

Well, for one garmin during the ride it shows no data, some data (like 60-80) or more probable data (like 120-130 but on a steep climb). All in turns. Then in the Garmin Connect, it looks like in the screenshot attached previously.

For the other, it was showing constantly unrealistic data without "breaks" in displaying... Since it is happening to both, I can only think that it is a software issue. We both updated to the new version yesterday. But I can see that it is not possible to roll the upgrade back, is there? We just have to... wait?

did you try to remove the hrm pairing , turn off the Edge completely , turn on, re-pair the HRM (via ANT and/or BT) and test? it looks like a periodically dropouts (i dont see how often but apprx in every 30secs or similar) so something got wrong in the Edge and caused conn. chip freezing. and try a soft reboot also, press and hold the power button at least 20secs until the reboot.

If it's bluetooth connection that is dropping, you'll be getting a connection notification on Garmin each time it reconnects. I didn't get connection notifications, but HR was showing "--" or "60". So, I guessed that connection stayed, just module had no data to send. There are 4 electrodes on the strap. Two nearest the module are resistance connections, the two smaller ones further out are capacitive connections. When I measured my strap, the capacitive connections had different values from each other. A new strap has same values on the smaller pads both sides. Also, pads should be wet for good contact when you put the strap on. Bad connections give dodgy readings.