The bug
The splash screen text, if overlapped onto any of the buttons, is rendered in front of the buttons, while the text shadow is rendered behind.
[media]Obviously, this is a tiny and hard to reproduce bug (I had to make a resource pack to force the splash text to be longer to get this screenshot after i saw it the first time), but it probably means that there are some other issues with the text and the shadow being separated.
How to reproduce
Open minecraft and go to the main menu, and reload the game until a long splash text appears (or force one to appear). Set the GUI scale to the maximum, and resize the window until the text overlaps with the buttons on the main menu.
Linked issues
is duplicated by 2
Attachments
Comments 6
Confirmed in 1.16.2.

Also, if the text is even longer, the splash text is rendered behind the button text
(The language is Esperanto)
@BoyrexMacaraya please add labels "splash" and "main-menu", maybe this could help to be noticed...
Confirmed in 1.16.4 and 20w46a.
Confirmed in 20w51a.
I cannot reproduce this in 1.21:
[media]
It is much harder to get the text to overlap with the recent changes to the GUI being centered. The text also does a good job of scaling to avoid overlap, but you can still force it. From my observation, despite the text being blurry you can still make out the text shadow properly rendering over the button (the darker yellow color)
Confirmed in 1.16.2 Pre-release 1.