Code blocks presumably exist for the purpose of including monospaced text such as source code in notes. It obviously needs to be displayed as-is, that's the whole point of the code block.
In some recent version of Evernote it appears to have started applying some auto-formatting inside code blocks, and replacing some characters. This doesn't happen at the time you type/paste the text, it affects when viewing notes which have existed for years.
For example I've just noticed this in one of my notes:
The actual text is:
= (or no operator): exact version equality
!=: version not equal
\>, >=, <, <=: version comparison
~>: pessimistic constraint, constraining both the oldest and newest version allowed. ~> 0.9 is equivalent to
>= 0.9, < 0.10, and ~> 0.8.4 is equivalent to >= 0.8.4, < 0.9
This is obviously a problem - this is a reference note and the text of the code block needs to be displayed properly as-is, not with characters replaced by other glyphs.
I'm on Evernote v10.82.2-mac-ddl-public (20240327123857) on MacOS Sonoma 14.4.1