I have heard random issues with video either freezing or just a black image - prob 90% iOS. Android seems to have less issues so not sure if it is caused by the iOS security updates breaking the dlink app or something related to the camera-app communication that gets broken. The mydlink Lite app is a different vendor and seems to run more smoothly, but this camera is not compatible. Can you try your 942L camera through the mydlink (not Lite) app? It will show up and is compatible - no need to reinstall it.
This is D-Links #1 selling camera (US - consumer) but have not heard of this issue a lot so I do not think it is a manufacture/firmware flaw since it doesn't affect every customer.
Unfortunately the 8xxxLH series cameras do not work with a PC/Browser like the 942L. If you want that feature, you may want to look at one of the older pan/tilt cameras (DCS-5030L, DCS-5222L). A lot more features than the newer line.
If you can get your hands on an android device, see if it has the same issue. If it does then it is definitely the camera.
On one device, I would uninstall the mydlink app, reboot, and reinstall. Login and see if the problem exists. If it does, I am going to agree that it is something defective with the camera. Problem is happening with multiple devices, multiple network settings, resets, different OS versions, etc.