I cannot recall the exact circumstances but in the past I recall viewing a stream (main or sub I can't recall) on an Amcrest IP2M-841 with IE11 and then bringing up the same stream later in VLC with the correct 0 or 1 for the sub-type in the URL that the resolution of one of the streams (again, long time ago, can't recall which stream) would be changed and I'd have to log into cam and set it back (main to 1080 and sub at 720).
I paid little attention because I use
Blue Iris. I updated the firmware a few months ago, it now works with Chrome and no plug-in and I just tried to replicate the effect I experienced above and was not able to. Maybe a firmware update will resolve it for you, if not the latest already.
Look at Amcrest firmware
downloads here.