conformToMask gives incorrect conformedValue on server-side

[lennoximus]

Hello there!

I'm using vue-text-mask in my nuxtjs project. Due to some circumstances, I need to convert incoming phone strings to appropriate masked format and it's done in global store state aka vuex via certain getters. Now, to the main point.
So the goal is: if I get the +79514787749 string, I need to convert in +7 (951) 478-77-49. The approach is as follows:

import {conformToMask} from 'vue-text-mask'

export default function formatToMaskedPhone (value) {
  const conformedPhoneNumber = conformToMask(
    value,
    ['+', '7', ' ', '(', /\d/, /\d/, /\d/, ')', ' ', /\d/, /\d/, /\d/, '-', /\d/, /\d/, '-', /\d/, /\d/],
    {
      guide: false
    }
  )

  return conformedPhoneNumber.conformedValue
}

As a result, if I debug my code on server-side, I get +7 (/\d//\d//\d/) /\d//\d//\d/-/\d//\d/-/\d//\d/ in conformedValue instead of the desired formatted string. On client-side, though, when my store getters are reevaluated, the resulting string is computed as I want it to be.

What can be the case of this behaviour? I can try to make a repro later, if this can help.