I know that this is not a serious problem, and I was very hesitant to report it or not. I am not sure if it only happens in Stack Overflow in Spanish which is where I am doing the reviews.
The problem is that when reaching the maximum number of daily reviews, normally a message is shown in which it is clarified that the maximum revision limit has already been reached and, depending on the time, the remaining time is shown to be able to carry out more revisions.
Well, this is not the case for the new review queue "First questions" and I'm not sure if the same thing happens for "First answers" since I have not reached the maximum number of reviews yet. It only shows an empty box without any text.
As you can see below:
And this is what it looks like in dark mode:
As I said at the beginning, I'm not sure if it happens only in Stack Overflow in Spanish.