By default, in the Graphing calculator, the angle mode is set to radians, However, in the “testing mode” (Desmos | Test Practice) the default angle mode is set to degrees, meaning that when students use default Desmos to practice for a test, and use “testing mode” Desmos during the test, they expect its angle mode to be set to radians, but it is not.
I’m not sure where the decisions for this are made, but similar to how you used to teach your students to check if a handheld calculator used order of operations, you may need to teach your kids to check what mode it’s in (e.g. if tan(45) doesn’t = 1, switch modes).