Not being able to configure DNSoverTLS with NextDNS

Hi, 

Please see - https://one.one.one.one/help/#eyJpc0NmIjoiTm8iLCJpc0RvdCI6Ik5vIiwiaXNEb2giOiJObyIsInJlc29sdmVySXAtMS4xLjEuMSI6IlllcyIsInJlc29sdmVySXAtMS4wLjAuMSI6IlllcyIsInJlc29sdmVySXAtMjYwNjo0NzAwOjQ3MDA6OjExMTEiOiJObyIsInJlc29sdmVySXAtMjYwNjo0NzAwOjQ3MDA6OjEwMDEiOiJObyIsImRhdGFjZW50ZXJMb2NhdGlvbiI6IkRFTCIsImlzV2FycCI6Ik5vIiwiaXNwTmFtZSI6IlZ1bHRyIiwiaXNwQXNuIjoiMjA0NzMifQ

I've been trying to configure DNS over TLS on my Linux Mint system. This is my resolved.conf file -

[Resolve]
DNS=45.90.28.0#243d5b.dns.nextdns.io
DNS=2a07:a8c0::#243d5b.dns.nextdns.io
DNS=45.90.30.0#243d5b.dns.nextdns.io
DNS=2a07:a8c1::#243d5b.dns.nextdns.io
DNSOverTLS=yes
Domains=~.

CacheFromLocalhost=yes
Cache=no-negative

StaleRetentionSec=1800

MulticastDNS=no
LLMNR=no
DNSSEC=no

DNSStubListener=yes

ReadEtcHosts=yes

But checking on 1.1.1.1/help says that no DNSoverTLS is there. I replace the DNS with 1.1.1.1, and then the DNSoverTLS comes.  Is this a nextDNS issue?

Please help troubleshoot.