Magnetized?

[JacksonStone]

Since I bought my 116610LN in December 2016, it has consistently been within +1 spd. However, within the last week, I noticed it's now gaining 3 - 4 spd. I know this isn't a gigantic amount, but it is three to four times the amount of gain as before, and that change has happened over a relatively short period of time.

I decided to look up watch magnetization, and read that one of the typical symptoms is the watch running fast, albeit usually many seconds to even minutes per day - far more than what my watch demonstrates. Several articles said to test for magnetism by holding the watch over a compass and seeing if it moves the needle. My Sub does indeed move the needle; another automatic I tested does not.

My questions:

- Does the compass test prove the watch is magnetized to a degree that would impact timekeeping, or is there such a thing as "harmless" magnetism? (I'm assuming it would not be possible for the needle to move in response to the watch if the watch weren't magnetized to some degree.)

- Is it possible the case and other magnetism-prone components of the watch have become magnetized, but because of the silicon hairspring, the effect on timekeeping is only slight?

- Could the change in rate be due to some factor other than magnetism? (I'm not aware of any change in my wearing or storage habits that would have resulted in the change.)

- Is this worth trying to degauss the watch myself, or taking it into my AD's watchmaker?

Thanks in advance.