According to this - https://support.garmin.com/faqSearch/en-US/faq/content/388HjIB8mK2OPz6vycgPb6 - my Fenix3 should maintain current EPO data by regularly syncing via GC. This is not happening.
I can manually update the EPO data via this 3rd party hack - http://www.javawa.nl/epo_en.html - but after about a week, the EPO data goes from "Current" to "Expired". The watch syncs itself via GC several times per day.
Fenix3 v8.00
Garmin Connect 3.12.0.1
phone is running Android 6.0