A couple of users are reporting that the "Trust this Device for 30 Days" checkbox upon login is not behaving as expected. They are having to enter in a 2FA code upon every login. They use both desktop and the phone app. They do travel for work, although I do not know to what extent. Am I misunderstanding how that checkbox works and/or are there factors I am not thinking about? Thanks.

Are you using Single Sign On? Those preferences are private to your org and will override NetSuite. AFAIK, 2FA is stored on a user's internet browser, so they will be prompted with each new device. A file gets stored on that device that expires in 30 days, but the user's browser might be set up to clear cookies when they leave a site for example. This would require their 2FA each time.

Also IP Address not just browser