As of 23w41a, it was stated in the change log that ''The name of non-living entities will now be shown if looked at and a CustomName is set, or always displayed if CustomNameVisible is set, similar to living entities''. This fixed MC-249408 and made it so boats show their name if named, but it does not apply to Armor stands, which are a non-living entity.
Also worth noting that on Bedrock Edition Armor stands show their custom name when placed. Although this is an older feature and does not apply to the current parity rules, its still worth mentioning.
Rexmanx
Thank you for your report!
We're actually already tracking this issue in MC-86164, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote or any additional information to the main ticket it would be appreciated.
Please be sure to use the search feature before creating a ticket to see if the issue has already been reported.
Quick Links:
📓 Bug Tracker Guidelines – 🛠 Community Support – 📧 Mojang Support – ✍️ Feedback and Suggestions – 💬 Mojira Discord