Thank you for the details, rjmelville.

I can't remember attachments being previewed in a separate tab. Clicking on them will always download the PDF copy to the local drive. Same thing with my colleagues. However, it's great to know that you're able to do that.

Aside from trying a different browser, you can also clear the cached files. However, if the same thing happens, you can contact our QBO Support to report this behavior. They can use a screen-sharing tool to see your setup.

Let me know if you have more questions in mind. Take care and have a good one!