How did you disconnect your DECT telephone?
You have to completely unplug it, from the mains, and it still might be a neighbors equipment, causing the problem.
As I stated I can't see how rain can affect your internal equipment, only your LNB, cable, connections, or dish reception.
I have read of cases where rain can get into the cable and flow all the way into the back of your receiver, but these are severe cases and take time.
Yes about DECT phone
And about the "rain " i can say that the problems comes only when it rain "strange"
And only on some TPs
Tested on Ex. a weak satellit 75E and a weak HD channel (Telekanal 360 HD) No problem.
But on Ex. SVT 1 HD 0,8W and Cmore Sport HD bad picture.
I will take my Duo2 to my naebor and see if it is same problem on his dish.
But must await for next rain ;-)