I read in an article (forgot where) that some sativa dom strains do that, trichs turn cloudy and some amber then after a couple weeks they go back to clear, so just take it the length of time the website tells you, there the ones that grew out that strain hundreds of times. I have no idea why this happens, but maybe what pauly said, it might have something to do with indica traits coming thru, then they go back to sativa, idk??
If I was you I would grow them for as many weeks as the seedbank said, you don't wanna cut down a sativa 2-4 weeks early, your yield would be shitty as hell and the high won't be nearly as good. I'm almost positive if you let it go another couple weeks your gonna see some trichs going clear, someone on this site made a thread about it like last month or something. The same thing happened to his super silver haze.