Nexus 5 Youtube App Problem

[AC Question]

Hello, I have a Nexus 5 (Android Version 6.0.1) and recently I've been having problems with my Youtube app. Basically it loads slow, especially the thumbnails, comments, and the search bar. When I play the video it works well, even in 1080p.
I tried to find the answer myself using google of course, but I have found nothing relevant.
*What I have tried to fix the problem :
1. Delete App Cache-data, reinstall it.
1.1. Restart the phone
2. I have also reset my entire phone.
3. At this point you think it might be an Internet problem, (I also did), so here is what I have done : Tested the speed of wi-fi connection : above 30 mb/s every time. (I tested if the app works better when I stay very close to the router). Even if I use a 5 ghz connection, Youtube is the only app which has Problems.
***!!! Here comes the part where my mind is blown : I've tested the Youtubeapp on much weaker wi-fi connections (from my university, from train station etc ) AND THE THUMBNAILS AND COMMENTS ARE WORKING GOOD. IT JUST DOESN'T MAKE ANY SENSE!!!!!!!
Why in the world this app works better on a weaker wi-fi connection??? I desperate need an answer, because mostly I use Youtube on my phone.
P.S Don't answer generic things, please answer only if you know what you're talking about.

 

[Golfdriver97]

Welcome to the forums. By weaker connection, do you mean the 2.4 GHz? The problem may be that the channels around you are congested.

 

[CR0ssi]

@ Golfdriver97 I don't what you understood but when I wrote weaker, in this phrase " I've tested the Youtubeapp on much weaker wi-fi connections (from my university, from train station etc )", those are public wi-fi connections. You share that connection with other people, I mean it muss be worse that the one you have home, no ? (I have a 100 mb connection home). More information : I've tested the youtube app with my brothers phone, a Motorola Moto G with 6.0 Android, which is less powerfull than my Nexus 5, and it works better, on the same wi-fi connection. The TV Youtube App from my Samsung Smart tv is also working good, on the same connection. And about the channels, I've chosen myself the best one, I know about these things. And one more thing : I also tested on my phone how youtube works within the chrome browser, and it works perfectly. Like I said before, it makes no sense to me, I can't find the logic in this problem.