Manual activities not counting towards distance

That's how it works. You have to record the activity with a Garmin device in order to have it counted towards distance. If the distance in the recorded indoor activity is not correct, you can edit it, and it will be counted. Not so for a manually added activity.

When I try do it on the garmin watch, for indoor cycle it gives me no info at all, no distance/speed/anything other than time on the activity, but if I did it with the “activity” running on the watch and edited it to have info on it would count?

Just use the Indoor Cycling activity, and enter the distance manually in Garmin Connect, once you finish and save the activity, if you cannot connect the indoor bike's speed and cadence sensors (and eventually also the power sensor) to the watch (which would be the simplest solution, of course)

Thank you very much