Let's perform some troubleshooting steps so you can access payroll and get you back to working order.
There are times that the browser is full of frequently-accessed page resources, thus causing websites, like QuickBooks Online (QBO), to act weirdly. Try logging into your QBO account using a private browser.
To use a private browser, here's how:
Google Chrome: Ctrl + Shift + N
Internet Explorer: Ctrl + Shift + P
Mozilla Firefox: Ctrl + Shift + P
Safari: Command + Option + P
Once logged in, go back and try to access payroll again to double-check.