Primary IPv6 dns server fails to respond

I’m using CLI on Openwrt, everything works perfectly except that the primary ipv6 dns server keeps on erroring out. 
 

Running the diag tool I get this error

Fetch error: Get "https://dns .nextdns.io/info": dial tcp [2405:7140:0:**::***:***]:443 : connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed be cause connected host has failed to respond.

How do I fix this?
Is something wrong with my setup?