Yes, we have discovered some things. Go to tab Custom URL. Change set stream type to something else than you had from the beginning. Change back to what you had from the beginning and save it. Hopefully it will work again. Or do a save between the changes might also be necessary. Test.
From your URL you use RTSP for an mjpeg format. For me that is a little mix of formats. Test the following:
-set stream type to mjpeg
-change rtsp to htttp