Currently the DNS request on non-53 port is blocked. User of Private DNS will have issue of "no internet access".
One temporary solution for user is to put custom script to get around the issue:
$IPTABLES -I "afwall" -p tcp --dport 853 -j ACCEPT -m comment --comment "DNS-over-TLS"
$IPTABLES -I "afwall" -p tcp --dport 443 -j ACCEPT -m comment --comment "DNS-over-HTTPS"

But, What are the recommended solution for the issue? Given the popularity of using Private DNS, please put the solution on FAQ.