My HR is reading very high (i.e., avg. of 160 in my very easy run today). This similar run has usually been in the 120s in terms of HR.
This higher heart rate has been occurring over the last ~6 months. Initially, I chalked it up to something with cold weather. But it has persisted into the warmer months. Occasionally, I will still get a run with an HR that I expect.
It doesn't seem like I have anything wrong with my physically. For example, my run today felt like my HR was in the 120s. Effort level on the runs is the same as it has always been.
I have cleaned the contacts on the watch as one form of troubleshooting.