Unrecgonized doi in the META REST Api

[SalvatoreDiMarzo]

There is an issue in the Meta REST Api, when putting inside of the HTTPS request a doi that contains the string '(issn)', the Api is unable to retrieve the information regarding the entity bound to it.
For example when making this request https://w3id.org/oc/meta/api/v1/metadata/doi:10.1002/(issn)1931-7581, no information is given.