Zwift ride doesn’t add to training load

Read the topic again.

Anyway, without dual recording you'll only miss out on training effect. Not a big deal. That is IF it's working however.

I may try this instead. So basically i would just start my Zwift ride and start a ride activity on my watch at the same time ? Once I'm done just delete the watch activity ? 

You would ride Zwift as normal, and at the same time record a Bike Indoor activity while making sure your watch is paired to your trainer. Once completed, end both activities, Zwift and Watch. Download the *.fit file from Garmin and Zwift. Use a tool such as FFRT to merge the two. The Garmin *.fit file is the base recording, while certain data points from the Zwift *.fit will be merged over the top of the Garmin. I use the Zwift GPS, elevation, speed, distance.  Once the merge is done you will have a third *.fit file. You then delete the original activity from Garmin and upload the third/merged *.fit file to Garmin in its place. It takes me about 1 minute extra to do all of this. 

Key point with this approach. Training load, status, affect are all calculated as you ride, in the watch. Garmin, for the most part, ignores the merged file when you upload it.

just downloaded this and cant seem to get it to work, it just added the two files together so i had effectively a double ride

I can confirm this worked for me too. None of the Zwift rides showed up in my Epix 2's exercise load chart until I logged a very short outside ride, then they worked fine. This is the answer I was looking for, thanks!

Have the same problem. Won't try the solution proposed by Droogles as dual recording, merging, deleting activities is too much of a hassle.

This should just work out of the box, Garmin! 

We're all free to do whatever we want. To each their own, but... 

There are other good reasons to dual record, other than being without a "hassle". 

1) The Garmin workout shows Stamina for certain watches, in real-time.

2) The Garmin workout shows performance condition for certain watches, in real-time.

3) The Garmin workout can be used as a backup when Zwift workouts get mangled due to internet outages, etc.

4) Certain Garmin watches have suggested workouts that factor in your physical condition and recovery needs as measured by the expensive watch which you paid good money for. These suggested workouts control your trainer, just like Zwift does. You can simply disconnect the controllable on Zwift and keep power enabled and still move through Zwift. 

What you call "a hassle", I call "more control over my workouts". It's bemusing that a person is willing to put in all the effort to ride, but an extra 2 minutes to dual record and merge is too much. 

People may or may not care about the features I've mentioned above, but thought I would mention them anyway.