Please change the order of how assigned and unassigned support tickets appear so that new, unassigned tickets appear at the very top of the page and all assigned tickets show below them.
New tickets that have not yet been seen should naturally take higher priority then those that have been assigned already, otherwise your current setup encourages new tickets to go unnoticed.
This is now even more likely due to WHMCS adding in this "Operator" badge and label and making ticket line heights even bigger, so fewer ticket lines can fit on a screen.
Sorting tickets by response time doesnt even change this, it still keeps the unassigned tickets at the bottom of the screen, below the assigned tickets. This is more of a "Fix the working logic" rather than a new feature.