wm_tag with calendar variables above 2 always returns string

The wm_tag with non-string calendar related variables above 2 ({c3ex},{c4bp},{c5ep},...) returns a string instead of the corresponding type.

1 and 2 variables ({c1ex}, {c2bp},...) returns the correct type.

You can easily test this with this code:
return type(wm_tag('{c'..(1)..'ex}'))..' '..type(wm_tag('{c'..(3)..'ex}')) --result: "boolean string"