We've had ours for almost 2 years and he seems to have done the same thing... he was just under 1000g, then stopped eating the middle of November and just took his first meal last week.

Thankfully he ate again this week, and during the whole time he only lost about 50g total, so I wasn't too worried. It did make us a bit baffled since he's never had a single problem before this.

Good to hear it's somewhat normal anyway.