I have the feinx 5x plus, and, with all fenix series I have owned, it works flawlessly with my tattoos. I just got a 245 and it doesn’t pick up my heart rate at all. It’s got to be a different or cheaper sensor, looks cheaper certainly, and was even less responsive on areas without a tattoo... this is bad news. If you’re changing sensors, and the new ones use what the 245 has, Garmin will be losing lots of customers likely. What a shame.