plgVmAfterUserStore $data object being overwritten

[derek webster]

Hi I wonder if anyone can help. Ive written a plugin that is supposed to overwrite fields in the userinfos table when the customer updates their information on the front end (or back end)
I am overiding the $data object within the plugin and if I add a die commant directly after my updates I can see that my Data is indeed being written to the database.
BUT If I remove the die then some other VM function (either a plugin or Native VM function) is then overwriting my data object.

I have this setup as a system plugin and is triggered with
public function plgVmAfterUserStore(&$data) {

My code
}

I've also tried plgVmOnUserStore

Ive also tried making the plugin Either 1st to load or Last to load.

I'm using VirtueMart 3.8.8 10472

Any help even to debug would be appreciated