It’s hard to avoid the fact that type-answer wants to strip out all formatting – but this is a unique twist. It’s doing an accurate comparison on a wrong answer, and only has a problem when displaying the correct answer you typed.
I’m able to reproduce it [on Windows, 25.02.x] using your text, but I’m not sure if that helps here or not. 
Let’s see if a dev can figure out what would need to change in the code.
In a correct answer [left], the screen displays the whole answer as class typeGood, and it “helpfully” resolves anything that looks like custom HTML tags, by manufacturing closing tags for them. In an incorrect answer [right], the screen alternates between typeGood and typeMissed, which seems to be enough to get it to leave the bracketed text alone.
From a card template design perspective –
Perhaps you don’t need all of that warning language on the card. It seems like simply displaying the correct answer – with {{Back}} on your back template – is enough.
I’m also going to presumptuously ping @Eltaurus and @Anon_0000 , since I know they have experience outsmarting this particular note type, and they might have advice that would help here.