The bug
All of its other subtitles refer to the block by its name so this seems inconsistent. Also the block doesn't really function as a portal either, with only one face visually resembling it. Not sure if intended.
Note: The respawn anchor ambient sound currently cannot occur in the game without commands, see MC-184066.
How to reproduce
/playsound minecraft:block.respawn_anchor.ambient master @a
Related issues
relates to
Attachments
Comments

Hi there!
I can confirm for release 1.16.2.
Can confirm for 20w46a.
Can confirm in 20w51a.

Can confirm this for 21w03a

Despite it quite obviously already being marked as such?
Can confirm in 21w05b.
Can confirm in 21w06a.
Can confirm in 1.16.5 and 21w08b.
Can confirm in 21w10a. Video attached.
Can confirm in 21w15a. You can use the following command to reproduce this issue:
/playsound minecraft:block.respawn_anchor.ambient master @a
Can confirm in 21w16a.
Can confirm in 1.17.
Can confirm in 1.17.1.

Can confirm in 21w44a.

Can confirm in 1.18 Pre-release 1.
Can confirm in 1.18.
Can confirm in 1.18.2.
Can confirm in 1.19 and 22w24a.
Can confirm in 1.19.2.

Can confirm in 23w03a.

Can confirm in 23w32a

Can confirm in 1.20.3 Release Candidate 1