Big change in AET?

I normally work on factuality tasks. Mostly rating target sentence factuality. Typically the AET is 3-4 minutes. Today the AET is 8-10 minutes. Is such a big jump normal, or could it be a mistake? I don't want to have issues with going over AET while doing more research.

I am a rater in the US and I have been doing this for just a few months.