I do not use drop box. Everything was working fine on the GT-AC5300 untill the last update, I noticed a bad lag on uploads, saw I was getting 10-50Mps on upload, normal on download. So I pulled out my RT-AC5300 which was a mesh router so I updated firmware back. and was getting the same thing, checked with ISP, hooked directly to Fiber Modem Im getting 1 Gig both ways. So I hooked up my old AC3200 and that is getting close to a gig both ways also. Trying to figure out if its a AC5300 thing.... or some new setting that doesnt play nice with my fiber modem for the 5300's?