PM5 maintains HR after disconnection

[nickt]

I have a PM5 with a Polar H10 chest strap, and it always connects without any issue.
I notice that the PM5 continues to display a HR value even after it has obviously dropped out.
I row 1:40 intervals for distance, and when it works properly, you see the predictable increase from start to end of the interval.
Sometimes, it will stay on a low HR value for an extended time (when you know your HR is approaching your max), or even more frustrating, slowly decrement! Then on reconnect, it goes up by huge increments to what you expect is the right value.
I know it is disconnecting, because I can even unclip the H10 from the strap, and the red heart stays on the ErgData app and it continues to display a HR value (usually decrementing over time).
Several PM5 firmware versions ago, the red heart icon would disappear so it was obvious it had dropped out. I suspect that the developers have added this "feature" to paper over brief drop outs and to instead provide an estimate.
Given that it is not immediately obvious when it has dropped out, I really hate this behaviour, and would much rather know it is unreliable.
Has anyone else experienced this?
I have replaced the H10 battery and alternated between ANT+ and BLE, but it still happens from time to time. I read some threads on replacing the chest strap, so will try that. How often do people change these? (based on 4-5 workouts per week)

[p_b82]

I've found that Ant+ is much more reliable than BLE - but I do have to follow a fairly constrained process to avoid mid work-out glitches.

1) get HR belt on - and polarH10 clipped in
2) wake up PM5
3) turn on phone BLE
4) open ErgData - let connect
5) start rowing within roughly 1minute.

If I take too long from it connecting to actually pulling the first stroke, things aren't always consistently logged.

I've replaced my battery in the H10 once about 6months after I got it, and I'm still on the original belt - roughly one year in and usage 2-3 times a week.

[MPx]

Don't have an Polar H10 - I use a Garmin and have no issues. However, FWIW, what you describe sounds more like chest strap issues to me than Ant or BLE (which tend to be more terminal rather than intermitent). I'm sure you know that the pads needs to be moist for best contact with the skin, and I guess if you are particularly hirsute that may also present an issue. My Garmin belt is about 18 months old and getting towards end of life (fraying badly) but still recording reliably - gets used neary every day.