According to the document serverURL, the serverURL compliant RFC8484, which is based on RFC6570, which is based on RFC3986.
According to the Section-3.2.3 of RFC3986, the URL should support the optional port number in decimal
3.2.3. Port
The port subcomponent of authority is designated by an optional port
number in decimal following the host and delimited from it by a
single colon (":") character.
port = *DIGIT
A scheme may define a default port. For example, the "http" scheme
defines a default port of "80", corresponding to its reserved TCP
port number. The type of port designated by the port number (e.g.,
TCP, UDP, SCTP) is defined by the URI scheme. URI producers and
normalizers should omit the port component and its ":" delimiter if
port is empty or if its value would be the same as that of the
scheme's default.
But I found that iOS ignores the :port specified in the serverURL and always connect to the port 443.
Is this intended or a bug ?