Fenix Watch Avg Power & Edge 130 Power Not Matching

This summer i completed an ironman, during the bike section i was tracking my power from my Vector pedals on both my Fenix 5 watch (Multisport activity) and my Garmin Edge 130 cycle computer.

Looking back at the stats the power between the two devices is significantly different.
Edge Avg Power: 180W
Fenix Avg Power: 212W
Given the ride was over 6.5 hours I would expect these number to be very close. Looking at the data in both Training Peaks and Garmin connect there are no obvious spikes or outages in the data that would explain this. Even looking at various sub sections its clear the two devices are just tracking at different levels.
Can anyone explain this, thanks in advance.
Karl