Apps don't work with IPv6 enabled in router So I've been having this issue for a while now where apps work fine over mobile data won't work when mobile is connected to otherwise perfectly working WiFi.
Some such apps are-


Discord (keeps on connecting and asks to check server)
Spotify  (keeps on loading)
twitter  (continuously loads)
google keyboard gif search tool while using WhatsApp (No gif preview and unable to send them.)


I'd like to mention that the same apps work great on other devices over the same wifi. I made a thread about it last week -

Here's my post on XDA which temporarily solved this issue

The temporary solution that doesn't work anymore was clearing phones cache and putting it on airplane mode.
Now I found a way with which I was able to replicate this 'bug'. Turning IPv6 off in my wifi settings. It worked, for now at least.

Using this guide's 11th given solution fixed my problem for now.

~So do I keep the IPv6 off without any consequences or is there a workaround cause from what I know IPv6 is important and it should be on.
Is there a better, more concrete solution?

Device-Xiaomi's Redmi Note 3-Kenzo
Root- No
OEM- Unlocked
Solution- Keep IPv6 turned off.
Reason- ISP not providing IPv6 connection so while it's on in the router settings it somehow stops my access to certain apps only on my redmi note 3. 
Yeah IDK but it's good enough for me.