Jonas Gierer

Confirmed

Could you try and test this bug with changing the setting of your keyboard? (Language options in control panel)
Test if it's also not working on AZERTY and QWERTY.

I changed my keyboard layout to en_us and it did not take a screenshot. (It's the backward slash \ by the way)

Do you guys use an AZERTY lay-out? Otherwise I could test it later.

The german keyboard layout is QWERTZ

Duplicate of MC-92 I think

Normally, that area should be light blue (fog):

What happens if you set your Render Distance down?

Confirmed (On a German keyboard layout as well)

Try this:
/execute @e[*type*=WitherSkull] ~ ~ ~ summon PrimedTnt ~ ~ ~ {Fuse:0}