This was not the case in 1.21.10, but is quite significant in 1.21.11. Turning off texture filtering and mipmaps does not make this effect go away.
Expected results would be the behaviour from 1.21.10 and prior. It may be a good idea to define the cross as its own texture (as was done before 1.9) so we don’t need to layer multiple textures on top of it to create the same visual result.
Can confirm - 1.21.11 Pre-Release 2
~ Happy to help!