Error "invalid Cookie ... dropping domain attribute"

Hi, I use Gin Web Framework (but in general it seems to me it is not essential). my site is running on a local network, so when use the address :9090, when trying to set cookies, ctx.SetCookie("ses", s.sesToken, SessionTTL, "/", s.host, false, true) where s.host is the name of the computer (not localhost) cookies are not saved if you pass s.host+":9090" cookies instead of s.host, but there are a lot of invalid Cookie.Domain entries in the logs "WIN-749BIOL2BEC:9090"; dropping domain attribute, is that how it should be and should I ignore the entries?

not relevant