I know this has been brought up during the snapshot phase of 1.17 (MC-225360). However, this now seems to be an issue (again?) even though it was marked as resolved.
Today we decided to start supporting 1.17 clients on our network and started receiving many reports of people not being able to connect anymore. The IP hadn't changed, people in 1.16 using java 11 (like me) can still connect. However, if using java 16 (required for minecraft 1.17, therefore all 1.17 players), the SRV records don't seem to be resolving correctly.
I can especially verify that this is the issue since the Mojang team added extra info: which numerical IP it's trying to connect to when it fails, the IP returned is the one specified under the A record of the domain specified as if typing it in the browser, not the one pointed to by the SRV record.

TLDR; (this is probably not exactly what's happening under the hood but it's what seems to be happening from an outside point of view)
Expected behavior: Using minecraft 1.16.x & Java 11

• If address in client: myawesomeip.com > SRV to mc.myawesomeip.com port 25565 > resolves A record of mc.myawesomeip.com > connection works
• If address in client: mc.myawesomeip.com > resolves A record of mc.myawesomeip.com > works

Errored behavior: Using Java 16 with any minecraft version (tested 1.17 & 1.16.5)

• If address in client:  myawesomeip.com > resolves A record of myawesomeip.com > fails
• If address in client: mc.myawesomeip.com > resolves A record of mc.myawesomeip.com > works