I'll interpret "greatly not crisp...not clean and clear" as you're now experiencing a lower picture resolution with Netflix on your new TG1682. For example, you now experience HD vs. UHD...or...1080i vs. 1080p. What is the resolution of your now unclean and unclear video?
You didn't mention if your SmartTV is connected to your network either wired or wirelessly. That makes a difference.
Your SmartTV negotiates with Netflix for the optimal picture resolution. The greatest factor to negotiate is your available bandwidth. If you have the available bandwidth and a movie is formatted in UHD, Netflix will send you the UHD version. If you don't have the bandwidth, Netflix will send whatever HD version is capable on your network, such as 720p, 1080i or 1080p.
To stream video, you should connect your SmartTV to your TG1682 with a wired connection. A wired connection is more consistent and reliable than a wireless.
If you can't go wired, you may have had a QoS setting enabled on your previous router for your SmartTV. QoS stands for Quality of Service. By enabling QoS, you're telling the router your SmartTV gets priority over all other wireless devices. You set your SmartTV as Highest Priority and all other clients on your wireless network will fight over the leftover scraps of bandwidth .
Go wired or Highest Priority.