Inaccuracies

Did you both start a walk activity and waited until you got a good GPS position and first after that you started to record?

Make sure you both have turned off auto pause: https://www8.garmin.com/manuals/webhelp/vivoactive4_4S/EN-US/GUID-6D3747A8-EB3E-4C32-9C06-C8AC081D0C84.html 

8305676 said:

Clearly my husbands device if not recording correctly how can this be resolved?

The best would be if you both shared a link to those activities, so that we can have a look.

However, if your husband's activity is more than 1hr longer than yours, then either he started it long before you, or stopped much later. Did you both started the Walk Activity manually, or used the automated MoveIQ detection? If it was the later case, it could explain the discrepancy. I'd recommend always starting and stopping activities manually. The automated detection is depending on diverse motion patterns, and they differ at each individual, so can never be identical for two different persons.

The Auto Pause, Andy mentioned, is a possible culprit, of course too.

We manually started our WALK activity recording at the same time. we both have motion detection but as this was an activity recording would Move IQ be an Issue?  The most identifiable error was when the activity was stopped and uploaded to Garmin Connect. We compared lap times and yes we are both using the same imperial measure, lap 1&2 showed no real difference in lapsed time but with laps 3 & 4 my recorded time was 19:08 and 16:58 respectively. my husbands lap times where 34:12 and 34:30 respectively. I am the unfit partner and it was a steep hill we climbed.  My husband stayed with me thought out the journey when I stopped he stopped, when I moved  he moved and so our times should have matched.

It sounds indeed like a problem of the Auto-Pause, as Andy wrote in his first reply. Since you were slow, it repeatedly paused your activity, cutting down the times. Do as Andy suggested and disable the Auto-Pause feature in the settings of the Hike activity.