Speedmaster 125 rotor issue?

I got my 125 from my trusted local shop last Friday. I, of course wore it Friday, Most of Saturday and Sunday (except when doing yard work). I took it off around 7pm and by 10:30 pm it had stopped.

I attributed it to a casual and minimal winding at the shop followed by semi-intermittent wear over the weekend. On Monday morning I wound it til I began to feel some resistance (Probably 40-50 short winds since the crown on these things is a little tough to grab). I wore it all day Monday and Tuesday (and not just sitting at my desk. I walked more than 2-miles with it on each day. And had it on my wrist for more than 12 hours each day).

When I woke on Wednesday at 5 am, I noticed it had stopped at 10:30pm. I shook it a few times and it did start. So, I rewound it today (Wednesday morning).

It's keeping time just fine, although it was about 30-to-45-seconds slow on Tuesday, hours before it stopped.

I don't mind winding watches, and I realize this watch is approximately 48-years old, but being an automatic...It should still function as such. No?

I'm going back to the shop/watchmaker tomorrow so he can take a look at it, but thought I'd ask you fine folks what you think. Thanks! Tony

To follow up, something was hanging up the rotor. Running like a champ now.