I would reach out to Wahoo customer support.
I had a Gen 1 Tickr that worked flawlessly for the past year. Midway thru that time, one of the electrodes on the strap became delaminated (still worked fine, but didn’t want to make it any worse with additional wear). I ordered a replacement off-brand strap from Amazon which worked great with the Tickr hooked onto it. I should have reached out to Wahoo instead since people have had success with getting replacement straps.
Anyways, a couple of weeks ago, I misplaced the Tickr unit so I ended up ordering a brand new Gen 2 Tickr. It paired instantly to my iPad running the TrainerRoad app. However, the readings were very erratic and completely inaccurate at times. For example, I did a ramp test and it detected my heartrate was lower at the upper steps vs. lower steps.
I reached out to Wahoo customer support telling them about the inaccuracies and even showed them the screenshot of the ramp test (with the HR line). They provided a list of things to troubleshoot. None of them worked for me, so they ended up sending a brand new unit that’s arriving sometime next week.