Vo2 max doesn't update after deleting activities

I have the same problem, deleted an accidental activity which messed up my vo2max, but it didn't change anything. Did you get an answer to this? 

Unfortunately I haven't. For me it means my VO2 max is way too high. 

So why don't you measure your VO₂Max again? The value is updating each time you perform an activity matching the criteria, it is not an average of past values.

Read the document HOW IS VO2 MAX CALCULATED ON MY GARMIN DEVICE? if you do not know how to perform an activity to update your VO₂Max.

The problem is the watch has pushed my VO2 max so high that it isn't seeing me hit my true 70% even for sustained activities. The fact that it holds onto the VO2 max from activities that were deleted seems backwards. 

That does not really sound believable. The last VO₂Max value should ovewrite the original value, regardless whether it is higher or lower. Much more likely your activity did not match the criteria for measuring the VO₂Max - please carefully reread all the conditions needed for the VO₂ calculation as listed in the document I linked previously. If you redo the activity exactly matching all listed conditions, and the VO₂ Max does not get updated, contact the Support and report it as a bug.

I did a run today and it updated my Vo2 max but it is still wrong. There is no way my Vo2 max is as high as it claims given my current state (stating it is 45). It still refuses to drop near what it was before (around 31) all my male spouse's stuff was accidentally imported. 

Was the high VO₂max measured with your device, or just imported from another one? What VO₂max value is shown on your watch? If it is wrong there, perform the master reset - as stated in the document How to Reset My Garmin Outdoor Watch, "Learned fitness values, for advanced fitness metrics, including: VO2 max, Training Effect and more will be reset during this process. The watch will need to relearn this data after performing a reset."

The high Vo2 max was measured with a Fenix 2, but my primary device is a forerunner 245. I have deleted the Fenix 2 as a device in the garmin connect, I have erased the activities I didn't do (but my spouse did with the Fenix 2 that got imported into my garmin connect on accident) and I have done the master reset. Garmin is still registering my Vo2 max as 43 despite multiple runs. In fact it says my training is unproductive because my fitness is "decreasing" when in fact it is overestimating my fitness in the first place. It will not let go of the high Vo2 max which is making it difficult to measure my actual progress.

I ran 2.5 miles in 32 minutes with an average heart rate around 160. My Vo2 max shouldn't be 43.

And what VO₂max did your watch (not Garmin Connect!) show after the master reset, when you did the first run after that?

It pulled the Vo2 max from connect somehow and still has it at 43. The Vo2 max has gone down from 45--> 43  over the course of multiple runs but it is still over 10 points above what it should be.