As of a couple of days ago I no longer see running VO2 max information. I still see cycling VO2 max even though I haven't cycled in months.
I run three times a week, 20-25 miles a week, so the data should be present (and has been up until recently).
If I view my data on the website I do have an option to see both cycling and running, so this issue seems to be on iOS only.
I'm including images from both the iOS app and from the website.
I use a Garmin Fenix 7.