No VO2Max for Bike Activities

You need heart rate and power data in your cycling activities for a vo2max calculation.

Why does it not calculate correctly?

Hard to tell, because you did not post any links to the Activities, but the conditions for the VO₂max calculation at cycling are as follows:

From the document VO2 Max Estimator:

In order to generate a Cycling VO2 Max estimate, you must record a cycling activity with heart rate and power from a power meter for a minimum of 20 minutes above 70% of your max heart rate. 

Ok, sorry, here is one but I added the power data manually because my watch does not save them.

connect.garmin.com/.../6059951036

I also have some activities directly from Zwift created with all data.

But both, Zwift and Garmin Activities with manuel power data does not show up in Vo2max.

I read that the activities has also be recorded directly by garmin sensors or devices (I have cadence and speed sensor and Forerunner watch) is this correct?

my watch does not save them.

In that case you cannot have the VO₂max estimate, since it is calculated by the watch, not by the app. It means even if Zwift has a powermeter, as long as it does not communicate the power directly to the watch, the VO₂max cannot be calculated.