Weird, as soon as my mouse pointer gets hit by one of the bullets, the shooters disappear until I refresh the page. Not getting hit for more than a few seconds

Weird, as soon as my mouse pointer gets hit by one of the bullets, the shooters disappear until I refresh the page. Not getting hit for more than a few seconds is actually rather tricky as the rate of fire increases. I didn't even notice them at first as my mouse pointer got shot by the first couple of bullets. Maybe the behavior changed.