Today i arrived in EDDM Gate 253. Aerosoft EDDM installed
You are missing the most important detail: which kind of jetways this scenery comes with ?
I can operate the Jetways via GSX, not via SODE.
Trying to assume from your sparse description, it seems the scenery comes with standard jetways.
After arriving i ask for Debording in GSX. Then i got a Message from GSX like "Dont forget to operate the Jetways .. " ... ok
That's what's supposed to happen when you are on a scenery that doesn't have SODE jetways. You will always see it, regardless if they are docked or not, because with standard jetways is not possible to know if they are docked, so the message will always shown.
But then i called again the GSX menu and the Operate Jetways. Then i got another Message from GSX like "Jetway operation requested ... waiting for other Service to complete" ... 
What ?
It's not possible to say more, without a precise explanation of what you did. You said "I arrived", but that doesn't say much. You arrived from *where* ? Which kind of jetways the departure airport had ? Have you used GSX on departure ? If yes, what you did, exactly ?
Then another Message from GSX like "No jetways connected, you will see no Passenger animation" .. something like that.
"Then another message" is not very clear. Do you mean after the first message it was waiting for other services to complete, this message came up on its own, or you had to do something to proceed ? You don't say which airplane you used, which of course is important, because maybe the airplane was finishing to perform some kind of GSX integration on its own, so GSX was waited for it, and then it proceeded normally. Again, this is quite normal, but it's difficult to say with a so sparse description.
Also, the second message about jetways is perfectly normal, when the scenery doesn't have any SODE jetways. As clearly explained in the GSX manual, in order to see passengers, the scenery must have SODE jetways, either provided by the scenery itself, or replaced using GSX. All the messages you said you saw (in addition to the fact you said you cannot control the jetways from SODE ) are the perfectly and expected messages you are supposed to see when a scenery doesn't have SODE jetways.
But that makes no sense at all. 
even if there are SODE Jetways or not
According to your report, it all makes perfect sense and it's all working normally, if the scenery has standard CTRL+J jetways. Instead, it will completely different with completely different messages, if the scenery DOES have SODE jetways so no, saying it's the same it's not possible.
I changed your very misleading subject to a more appropriate one, and moved your post which you mistakenly posted in the wrong section ( the GSX backdoor, which discusses previews of new features ), and moved to the proper support section instead.
