Apparently, when you tell DOOM (2016) that you want to "restart level", it doesn't just take you back to the start of the level. No, it wipes all the progress made on that level – and any progress made after that level was completed, including later levels and secrets found on previous levels.
You could have been just a smidge clearer on that, id Software.
I am so pissed right now. There's nothing more demoralising than having to redo hard work. *sighs* Way to make it un-fun.