Hello all...this is my first post here. My coworkers and I ran into this issue with our new outdoor mesh router and since we tore our hair out trying to figure out what's wrong I figured I'd shared it here in case anyone else runs into this issue.
Apparently the passwords on the MST200 can only contain alphanumeric characters. This wouldn't be a problem, except that it doesn't indicate that on the password change screen and it will accept a password with special characters. Then when you reboot the device and try to log in via the WMI you're locked out. It does (weirdly) let you in via telnet, thankfully, so we were able to get in and change the password.
I just thought this was odd and hopefully posting it here will help someone else in the future.
Of course if we had read the full user guide beforehand ;-) we probably could've avoided this.... but where's the fun in that? :smileylol: