proxy host SSL redirect url wrong

[cdebackere]

I just set up npm, latest version in docker

I added a proxy host, linked ssl certificate and select the option Force ssl

when going to https://mydomain all is ok
when going to http://mydomain i I get forwarded to https//mydomain . the ':' is missing and as a result the client/browser gives an error

is this a configuration issue of the npm or the host, or is this a bug?

BR
C.