Hi, it seems that when I try to use the Backup/Restore all teams button at the bottom of teambuilder, something about the Tera type doesn't get saved if you've reloaded the page and use it. However, a way to remedy this is to manually open up a team first, which will recall the proper Tera type you set, then if you use the aforementioned button it has the correct Tera types. This gets a bit cumbersome with a larger number of teams and can fairly easily lead to resetting your Tera types if you don't know about it.
here is a video to show it a bit better