Firstly I'd like to welcome you to the forums and say that I'm sorry to hear that you've been experiencing some issues with the Netflix app, and also for the delay in getting to your post.
I've run some checks, and can see that your set top box seems to be displaying an issue with the hard drive, and there are some other network issues which will not help.
The reference for the network congestion issue is F006526207. This has a review date of 09/01/2019.
However for the hard drive issue, I'd like to look into booking a technician to call out and take a look. I'll pop you a private message, please look to the top right of this page, where you'll see a purple envelope icon, click on this and you'll see my message.
Many thanks and apologies once more.