IP Cameras over CG-NAT?

[nzoomed]

Not sure if it's of any help but I run 7 Dahua cameras with a Dahua NVR on Skinny fibre. No static IP. Skinny fibre/vdsl/etc used to be behind CGNAT but that was 4 ~ 5 years ago.
I use DMSS app on my Galaxy to view the cameras which works well. NVR has a 2tb HDD which stores 12 days footage from the 7 cams.
The current setup was done 2 years ago and I've forgotten if I had to do forwarding. It was reasonably simple as I recall.

That app was likely going through the cameras own cloud gateway service.
Reolink have the same thing, I have been using those fine on CGNAT, but notice that at times the footage jumps around while doing replay, apparently that is a common thing over CGNAT, I don't have this issue with any of them connected over fibre and I know the bandwidth was sufficient enough on the 4G connection to handle it.