Forerunner 945 - Software Version 7.20 VO2max Calculation

I don't use the tips but VO2max works perfectly with both the old 7.10 and the current 7.20

There was a post about the Body Battery being stuck at 5 with the new firmware after a hard reset.  Blake from Garmin responded and said something about it being locked at 5 (could see same with vo2 issues) until there was enough trend data to give a good value.  Seems a bit fishy... but... could be similar.

Since my update I have had plenty of vo2max updates for biking on my indoor trainer.  I had done a restart of watch after update, (light button for 30seconds or so)

I agree with you. Since upgrade to 7.20 I do not have any info about VO2Max  after running and 7 days load is frozen too.
Garmin has introduced some bug. When upgraded the device made something strange. VO2Max data was deleted.

Same problem, hope for a software update soon

Works fine for me. Have training load, VO2max, body battery etc. 

Same here. I do have VO2 and TL daily value updates even running only on Z2.

Have you tried a hard reset + 7 days outdoor activities with different intensities? I would also go without any widgets / GIQ stuff just to be on the safe side on the first 7 days.

I have made a hard reset and VO2max estimate and training status are working again.

You did nothing wrong imo. I experienced the same issue, suddenly since last week (update has been done couple of weeks ago). And all of a sudden the training status reappeared today after a run (my only run for this week).

But after the training status reappeared something else disappeared, most of my running statistics, like vertical ratio, step length, gct, balance.

My feeling is it has to do with the most recent update.