FW 7.00 & 7.10: vo2max don't sync to Garmin Connect anymore | Time Difference without GPS and no NTP Protocoll

And your Physio TrueUp is on?
It could be, that after an update it got reset to off

The same for me on IOS and between my 830 and garmin connect. I think it's a bug from garmin not the Edge

it is somehow incomprehensible that an existing and functioning WLAN connection transfers the vo2max values ​​no longer to the other day.
If you delete the WLAN connection and record/end a new workout, the vo2max is also transferred again, but only via BLT (Garmin Connect Android)

Who kills the WLAN transmission of vo2max (Garmin Express do always strange things, when you connect your devices to the PC)?

Did You switch off completely your 830 or just put it to "sleep" mode with short button press? And after indoor ride? I experienced the same since months just i was lazy to report it...

and the calibration prompt message doesnt work after sleep mode, only works if the unit was switched off conpletely and switched on. It was a known bug in older Edge units too (1000, 820 etc...)

i never use sleep mode, i use switch off completely, atm indoor rides only, it works again since i removed WLAN complete from my Edge, calibration prompt for my Vector 3 are working always

As i know the altitude acclimatization works only with sleep mode (it is checking the altitude at midnight or what.. and cant do it if the unit is switched off) . Try your unit with sleep only and check the calibration prompt works or not (it wont :))

Probably the only indoor rides atm could be problem for Edge fw, try to record an outdoor ride (even during indoor session with gps on setting) and check what will happen.

I prefer not to try such things anymore, as I used the sleep mode last time, the battery suddenly ran out during the next training session, which is quite annoying.

After all, the vo2max transmission via BLT now works, suddenly the graphics in Connect (Android & Web) where the history of the performance-related threshold is displayed shows now values and a history since 15 of february (never seen before working), is a coincidence or has something been improved in the background?

Who needs WLAN for vo2max, when BLT works! 

the problem comes from following:

again there should be a bug in the firmware, again the Edge loses time again and is not syncronized to a time server (NTP) if it is only used indoors (only some minutes, but to much).

As soon as there is a time difference, these problems occur with WLAN, although via WLAN you could access an NTP server

It looks like every second or third firmware release thos proble came back :-\