Forerunner 245 not holding accurate max HR (defaults to age prediction after every activity)


I am having trouble with my FR245 holding an accurate max HR used for the performance metrics calculations. For example, it defaults to the 220-age formula (177 in my case) however my true max HR is measured at 192. I have followed instructions and manually changed this to 192 in the "user profile" then "max. HR" setting. The watch will hold this until completing the following run when it resets back to the age predicted max. I have also tried letting the watch automatically measure my max HR under the "Physiological settings" then "Auto detection" and have run reaching a HR of 192. However, the watch also still defaults back to the age predicted formula. The low estimated max HR is throwing out many features such as heart rate zones and race time predictions. Does anyone have similar problems, or know if this a known bug that is being fixed? Or, is there something else I need to do? For now, I am entering a fake age into the watch and Connect.

Many thanks,