Greasy Fork

try fix with:
document.querySelectorAll('[class*="endscreen"][class*="button"]:not([style="display: none;"]) a[role=button]')[0];
work fine.

querySelectorAll because of [role=button]

var autoPlayNextRightAway = setInterval(function() {
    var e = document.querySelectorAll('[class*="endscreen"][class*="button"]:not([style="display: none;"]) a[role=button]')[0];
    if (e) {
        e.click();
        autoPlayNextRightAway && clearInterval(autoPlayNextRightAway);
    }
}, 100);

OUUPS!!
BAD TYPING.
HERE IS THE GOOD CODE.

autoPlayNextRightAway && clearInterval(autoPlayNextRightAway);

var autoPlayNextRightAway = setInterval(function() {
    var e = document.querySelectorAll('[class*="endscreen"][class*="button"]:not([style="display: none;"]) a[role=button]')[0];
    if (e) {
        e.click();
    }
}, 100);