VO2 max recorded for Trail Running although deactivated (Enduro 2)

Hello. 

Although I have the option “VO2 max” for Trail Running deactivated, VO2 max statistics have been modified after a Trail Running activity. 

Please,

- is this a bug?

- is there any option to delete the record of the VO2 max in a specific Trail Running activity, without deleting the activity? 

Thanks in advance.