Text sprites sometimes render over username/commands suggestion box in chat unlike normal text that renders under

Disclaimer: I am not a good explainer, so please check back and forth on my linked screenshots to understand better please.

In the chatbar, Minecraft can suggest a few usernames based on what you’re typing, or commands. That opens a panel with all the suggestions. Said panel renders under some sprites that are in the chat.

How to get to it:
Run this example command (in a command block)

/tellraw @a ["   ",{"sprite":"item/porkchop"},{"sprite":"block/stone"},{"sprite":"item/diamond_sword"},{"sprite":"block/diamond_ore"},{"player":"Dinnerbone"},{"player":"player_314159265"},"\n\n\n"]

It will say in chat a few sprites to test which ones go under or over: two items, two blocks, and two profiles (In the end though there was no difference. Good to test anyways). Then, open chatbar and type “/” which will suggest every command. That will open the suggestion box.
What is looks like:
I noticed that sometimes sprites render over the box (but always under the actual text in the box)
What it should look like:
It should be on the same z level of actual text, so it renders under the box.

Which instances does it go over and when does it go under ?
I am not sure, but from what I’ve gathered:
under: - If the sprites are in the first message containing sprites that appear in chat (before scrolling up and down). For example, after F3+D, after joining the game, or if when opening chat (before scrolling up) the sprites don’t appear anymore because they’re too far up to be shown.

-If they are somewhere else than chat (on a sign, on a custom name, etc…)

-If the message the sprites are in contains regular text.

over: -If the sprites' message are not the first one to show in chat (before scrolling up), they will render under.

Note: it might not be clear from what I’ve said, but even after scrolling up, the sprites keep their status, and will stay under or over like they did the first time being put in chat.

Images:
-Image 1
Goes under because it’s the first that is shown in chat

-Image 2
First goes under because first that is shown in chat; second isn’t first and goes over the box

-Image 3
First goes under because first that is shown in chat; second goes under because contains text

(-Image 4
Show what image 3 looked like without the box so it’s easier to see)