Thanks for bringing this to our attention, @x2bate.
It could be that the stored cache and cookies are the reason why you're unable to update your team member's e-mail address in TSheets. Let me share some basic troubleshooting steps that will help you get back to work.
Let's start by accessing your account using a private browser. This doesn't save your site data and visited pages. You can press the following keys to access this mode:
Press Ctrl + Shift + N (Google Chrome).
Ctrl + Shift + P (Firefox).
Control + Option + P (Safari).
If you're able to change your team member's email address, let's go back to your regular browser and clear the cache to delete the junk files. If the same thing happens, we can use other supported browsers in the meantime so you can get to your tasks. The one you're currently using may have temporary issues with TSheets.