As of recently I am experiencing the same issues. For the last rides the strap response was erratic. To be honest I do not get those huge steps from 140 bpm to 100bpm, mine are like from 155 to 145, but still I consider the response could be the same as for a faulty sensor/connection between sensor and strap. My ticker worked fine and I regularly change the straps, once per year more or less. I also wash them in the washing machine in a dedicated clothes sack. I do not understand, as my setup is unchanged, no new ANT+ or BLTE connection, I use the same setup as before, so I would exclude interference connection in this moment.
I will probably change again the strap or wash the current one which is just a few months old. If this does not solve the issue I can only assume the tickr unit( sensor) itself is faulty. I will give the Wahoo Utility app a go to diagnose and also reset the tickr sensor using the mentioned procedure.
Here is a printscreen from Strava on a ride done on Zwift yesterday. It is just part of the ride where I zoomed in to better reflect the behaviour: after the first sprint the heart reaches 158bpm and then for more than a minute it stays there, and there there is a sudden drop. for the second sprint it mildly goes up (when in reality it should have gone up as in the case of the previous sprint) and right before the sprint effort is done it does not bulge anymore and stays there… Finally on the last minutes, even though the power is constant and cadence as well, there as stepwise drops in HR.
What are your thoughts?