Omega Speedmaster - not running

Dear All, I need your advice.
I put on this morning my Omega Speedmaster Professional, cal. 1861, ref. 38705000, after a two weeks stop. It was safely stored in his own box, it suffered no hits, no water exposure.
I tried to wind it as usual, and noticed that:

1. You can wind it forever, the crown doesn't stop turning.
2. The hands don't move. The watch doesn't tick. It is stopped.

I already wrote to the local assistance, today they are closed (being Monday). Meanwhile, while waiting for a thorough check, do you have any suggestion/hypothesis?

Thank you in advance,

That was my first thought. Quite strange, it had been serviced one year ago, back in April 2024.

It was an independent lab, although a trusted one. I will bring them the watch tomorrow and ask for a check.