Already did so, as stated. I sent a screenshot from a server, and I sent a screenshot from a singleplayer world, I had created 20 minutes before making this post, killing 20 ender dragons to get the complete result. The screenshots that you see, where I am in creative is the singleplayer world.
Otherwise, I am misunderstanding what you mean by vanilla client singleplayer. I am playing on "Latest release 1.14.4", no modifications.
Edit: So, I went and made another world, this time without using "latest release 1.14.4", but making my own.. Instance? It can been seen in the Imgur link relating to this comment (It comes further ahead). Result: Same as always, this is the 3rd/4th world, I don't know what I can do more to prove that this is something that bugged out in 1.14(possibly 1.13), creating a difference. Here you have the link, and any further questions, please just ask... I'll be, I guess, happy to make yet another world, though I don't see what purpose it'd have. Also, the instance is called "Bug Report" so that I could find it in my launcher.
https://imgur.com/a/TCs4TEb
Okay, incase we're counting a server (that runs on either Spigot, or Paper. Couldn't figure out which one), then the screenshots provided where I am in survival shows it. The dragons were killed in 1.14/1.14.1, if I recall correctly.
Incase we aren't doing that, I went and made another world, killed 20 more enderdragons, went and checked the same coordinates (also, this doesn't apply to JUST those two, it applies to all of them, but I feel like sending 20 screenshots would be unnecessary, though I did provide another example, this example only being shown in the fresh world). The screenshots where I am in creative, in that case, is the 100% newly loaded world where all I did was /setblock ~ ~ ~ end_portal, killed the dragons, and took the screenshots. It is run with "Latest Release" as my launcher version. Also, I don't know how to provide screenshots in a comment, so I'm going to post an Imgur link: https://imgur.com/a/upITgRM
Edit: The server runs on Paper, just got clarification from the owner.
That there is just what I needed as further proof. Thanks!