See the last part of this ("Additional Background").

Today we analyzed this issue further and have found that it is related to the DCOM permissions which were added to ASCOM components 10 years ago in order to make them compatible with TheSky 6, which uses DCOM for the old SB Internet Astronomy Suite. Those LocalServer components which do not have DCOM compatibility info registered with them will accept inbound connections with no problems. This is why some things work and some don't. Unfortunately, the Installer Generator tool for ASCOM driver developers has this DCOM stuff baked in. Rather than risk compatibility problems with TheSky 6 (and yes there are still people using it), the right way to fix this is to change the DCOM authentication level as described in our article, and doing this within the Installer Generator.
There is noting "improper" in the drivers. There is nothing "improper" in the way they are registered. This post is unnecessarily negative. No one could have guessed. And the whole thing is a result of some junk DCOM info needing to be present in COM registration just (and only) for TheSky 6 ten years ago! I was around for all of that. Thanks for alerting me to this. I will get onto the SGP forum and fill in the blanks. Man there is a load of BS around this.