Unfortunately this is being caused by static electricity building up in the electronic controls in the handle of the hose. I've seen this problem on numerious occasions, and in fact I have the twin brother of the Blue Moon, or the Silver Moon which used the same hose, and has the same problems in my own home.
The good news is that Miele has redesigned the hoses to fix this, and I have never seen a single problem on the newer style hoses. I guess the bad news is that the hose is not cheap.
I would recommend to you to go ahead and purchase the new hose. The average life expectancy of your Miele is 20-25 years, so you still have a lot of life left in your vacuum.
Here's a link to the SES125 Hose that fits your Miele Blue Moon on our website:
To change the hoses out, simply push the two tabs on the end of the hose that plugs into the vacuum, and pull the hose backwards until it disconnects. You'll see on the end of the new hose electrical connectors. Simply line these up with the opposity receptacles on the canister and push the hose down until you hear a snapping noise.
I really hope that this information was helpful to you. If you have any follow up questions, or would like a clarification, please use the comment box on this page.
If this was able to help you fix your machine, please be so kind and rate my repair or leave me feedback. This is really appreciated.