Audio/video sync with amazon fire stick

I have 3 amazon fire sticks. I get video stutter and audio/video sync problems with all fire sticks. I have no problems with my iphones or ipad or computer. wifi signal is good. I am using a new tplink archer c9 router. It works great with every other device. I like my new Tablo so far except for this problem. I havn’t noticed this problem when playing back recorded tv.