I was wondering if you have found a solution to this issue because I am experiencing the exact same problem.
Thank you and regards,
Sorry, I haven't. I have only found information that leads me to believe that the day of using self-signed certs is soon passing, if it hasn't passed already. I believe that this is because the publisher is always going to be "UNKNOWN", and there is no way to change that if using self-signed:
It seems the days of allowing the user to decide for himself how he wants to use his computer are passed.
Thank you Allasso, I will proceed with this in mind then.
Take care and all the best,