Checked peg etc earlier, it's seated in the hole. And the wiper on my car also gets stuck about halvway.
Talked to my BMW shop today as well as an independent workshop. Both guessed it was most likely a bearing failure in the wipershaft pivot (item no 10 in this OEM-part overview: http://www.realoem.com/bmw/showparts...&fg=45&lang=en
Got a service date set for the 17th of May, I'll get back w more info after that.