Wrong live data on garmin forerunner 55 but good in garmin connect

Hi,

My wife has a Forerunner 55 and I have a Forerunner 255.

When we run together, the pace of her 55 is a lot lower than mine (for example : 12min/km for her, 6min/km for me, same pb for the distance, ...).

Also it takes several minutes for her 55 GPS to acquire satellites positions.

At the en of the run, when we synchronize our watch to Garmin Connect. All the data of her run are good, the pace is 6min/km like mine, the distance is good.

Is it a know issue? Is there a solution to solve it?

I don't understand why the data on the watch are wrong whereas they re right in Garmin Connect.

Thank you.