My GL.iNet DDNS has also been failing for the past two days.
DNS queries to glddns.com do not resolve. The authoritative DNS servers (NS1.GLDDNS.COM, and NS2.GLDDNS.COM) are pointed to an AWS ip address 44.235.104.247. Queries to 44.235.104.247 fail. For example:
*dig A +noadditional +noquestion +nocomments +nocmd +nostats zxxxxxx.glddns.com. @44.235.104.247 returns:*
**;; connection timed out; no servers could be reached**
Here’s a post about the same problem: https://forum.gl-inet.com/t/glddns-com-not-resolving/37743/10