User expirity resets after rule fires

Question

I have a rule, that sets user expiration date from a date field (this is on the same user account, I need this for another rule). However, after the rule fires the user expiration date is beeing reset (in case no other data was set there, otherwise it gets back to the previously set date). That means the rule works but it is useless, while something is overwrinting it. the question is, why does user expiration resets.

The rule exported:

{ "rules_set_user_exp" : {
    "LABEL" : "set user exp",
    "PLUGIN" : "reaction rule",
    "OWNER" : "rules",
    "REQUIRES" : [ "rules", "user_expire" ],
    "ON" : { "user_update" : [] },
    "IF" : [ { "NOT data_is_empty" : { "data" : [ "account:field-exp-date" ] } } ],
    "DO" : [
      { "user_expire" : { "account" : [ "account" ], "expiration" : [ "account:field-exp-date" ] } }
    ]
  }
}