First, NTP is UDP, not TCP. This explains why some of your tests ended up in no responses.
Next:
I have the same behavior, I haven't noticed a change since version 19 or 20.
On a client: ntpdate -q 192.168.1.1
This works for me, which made me wonder why. The answer is IPv4-mapped IPv6 addresses. See:
- https://lwn.net/Articles/688462/
- https://unix.stackexchange.com/questions/152612/netstat-why-are-ipv4-daemons-listening-to-ports-listed-only-in-a-inet6
root@OpenWrt:~# sysctl net.ipv6.bindv6only
net.ipv6.bindv6only = 0
No, It would be 0.0.0.0:* if IPv4-only