Hotspot Page Gives Confusing Feedback

Hi, first I’m sorry if I post this in wrong category (general or user manager subforum).

I just updated my router to OS 7 and setup Hotspot with User Manager and RADIUS server.

I spent hours and frustrated because it’s always gave me response “RADIUS server is not responding”.
Today I just find out it’s not my setup problem, it should says “invalid username or password” when I input wrong user or password but instead it give “RADIUS server is not responding” feedback.

Is this a bug or I did something wrong?

I tried resetting the HTML to default but the issue still there.

Anyone?