@Ameen , Ive also been having problems with
Netflix streaming, mainly since last 2-3 months. Sometimes it drops from 4k to hd. Very seldom to 720p, when it becomes noticeably bad. Testing netflix (using its app's test network option) shows only 30 mbps. It was earlier close to 100. Perhaps you could check this option also.
The same device, using same network is able to steam
Amazon prime at 4k.