The RTSP streaming i.e. NVR recording seems to have broken at some point. I remember testing it way back months ago and it worked as it should but now a few firmware releases later when I tried it again it doesn't work anymore.

The camera account section says "At this point the NVR recording will be disabled", and it instructs to remove the microSD card. I've done this, I've tried everything I could think of but the RTSP stream just doesn't work. With mplayer I was able to a get a Unauthorized exception from the stream so it seems that the credentials of account section doesn't work as intended or something else is terribly wrong with the streaming.

$ mplayer rtsp://192.168.2.99/stream1 -user <my user name> -passwd <my password>
MPlayer 1.3.0 (Debian), built with gcc-8 (C) 2000-2016 MPlayer Team
do_connect: could not connect to socket
connect: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

Playing rtsp://192.168.2.99/stream1.
Resolving 192.168.2.99 for AF_INET6...

Couldn't resolve name for AF_INET6: 192.168.2.99
Connecting to server 192.168.2.99[192.168.2.99]: 554...

librtsp: server responds: 'RTSP/1.0 401 Unauthorized'
rtsp_session: unsupported RTSP server. Server type is 'unknown'.
libavformat version 58.20.100 (external)
Mismatching header version 58.12.100
libavformat file format detected.
[rtsp @ 0x7fe6b7680de0]method DESCRIBE failed: 401 Unauthorized
LAVF_header: av_open_input_stream() failed

Exiting... (End of file)

This is a deal breaker for me for my future needs if the RTSP stream doesn't work and I will need to seek another manufacturer that provides cameras with working RTSP stream so I hope this is just a minor glitch and gets fixed asap.