Heart rate wayyyy off

I have a Garmin fénix 5x plus. While this is an older model, I bought it brand new summer 2021. The heart rate is inaccurate more and more often. I can push myself to the limit during a workout (run, bike, interval training, etc) and it will say my heart rate is less than 100. While I’m probably closer to 170.

Anyone experienced this? Should I call Garmin? Factory reset? Water damage?

Thanks, Garminites.