VO2

What do you mean Garmin Connect on PC, WEB version?
Are you sure that your watch is assigned to the same account you logon?
What your Garmin Connect mobile is showing?

The same email address is set up on both devices. Also i regularly syncing with the PC connect app. I don't get it why it is different?

It is strange.
Garmin Connect on mobile is only other way to present data from WEB.
Asking again: do you see different data on your mobile Garmin Connect and WEB Connect?

Weird.
Only one what I can assume, maybe these VO2Max are for different sports. You can have separate VO2Max for running and cycling. But it is only guessing.

I think, you should call Garmin support.

Yeah well... thx anyway. One thing came up in my mind, that when i bought the new watch, and sold the older one, i registered the new one, with the same account. So if on the old one was a good VO2 maybe its summing up the results with the old one, and that's why is registering different VO2-s . But than if it syncs why does it like this? 

What device do you have and what did you have before?

I've changed and added many devices and not had this issue , apart from when the new format GC was setup recently and I had some small discrepancies between GC and the watch but that seems to be OK now..

Have you tried resetting the watch completely and resetting things up from that clean base , as then one would adssume the VO2 would pull from the Connect system , but it may depend on the device.

But if i look at your posts , the difference is between Connect Web and Connect mobile also? Is that correct?

Have you deleted connect app completely from your phone and reinstalled it from clean also.re-pairing your watch also.?

I had a Fenix 5 and now i have a 6X Pro Solar. I didn't reset it, because i don't want to lose the progress....but it seams i will need to.

Try doing the remove device from app pairing , uninstall and reinstall the app and re-pair the device first.

Check list of devices registered to your account and remove these you don't have.