Received a response from the Fed Ex rep: no new information. And Sarah emailed to say she's been in contact with Fed Ex Germany yesterday and today but still no updated delivery date. She's very apologetic and continues to say all the necessary paperwork was submitted and resubmitted. She's continuing to work on it, which I appreciate.
Edit: I just found a followup email from Sarah from this morning that went to my "Junk" folder. She advised that Fed Ex is returning the watch to Stowa. Sarah said FedEx Germany is now investigating what went wrong here. In any case, once they get the watch back, they will then re-send it to me but first make sure it doesn't end up in the same status as before.
Kind of sad but also kind of a relief.