M24 Compatability

We have a new client that has approximately 20- M24 cameras. Is M24 the same as M24M? We are able to get to the login screen but unable to login using a web browser. It seems like a browser issue because it does not ever show that the password is incorrect, but reverts to the “enter credentials” window. Have tried numerous browsers on both Windows and Mac, they all seem to behave similarly. We have also tried the MXManagement 1.5 and that does not work either.
Wondering if maybe there is a way to continue using these cameras?

M24 are the same as M24M.
IIRC wrong password message is not shown if ip filtering or “intrusion protection” is enabled. You’ll only get an error if you cancel on credential entry dialog.
I’ve had even older cameras connected through modern browsers (edge/firefox) so it’s probably not browser.