My "Stack Overflow Meta" site details are not listed in the API, when I'm adding the "meta_site;main_site" in the types filter.

        [/2.2/users/2855348/associated?types=meta_site;main_site][3]

But where as, if I filter with meta sites only "types=meta_site", I can see the "Stack Overflow Meta" details in the API result.

        [/2.2/users/2855348/associated?types=meta_site][2]

  [1]: https://api.stackexchange.com/docs/associated-users#ids=2855348&filter=default&run=true
  [2]: https://api.stackexchange.com/docs/associated-users#ids=2855348&types=meta_site&filter=default&run=true
  [3]: https://api.stackexchange.com/docs/associated-users#ids=2855348&types=meta_site%3Bmain_site&filter=default&run=true

Is this a bug or I'm missing any?