Hello guys,
I come to report what happened to me, I searched for a lot of information on this topic, after all I had a problem similar to yours.
I bought on the aliexpress the NVR DS7108-SN / P. I also bought two types of IP cameras, one just connected the POE port and it worked perfectly, but the other was only working after update (I put the latest firmware version I found) and it worked perfectly.
So I decided to update the NVR firmware. The same came with firmware multiple languages, so far so good. I found that if you wish to use the latest firmware version you only have in Chinese language, then I recommend that you do not waste your time trying to update this NVR for new versions, because the only difference I noticed was the security, however, if you do not read Chinese is best to leave the previous one. I was forced to return the firmware (downgrade), whose procedure appears in this topic in previous messages.
Another problem I had was with ezviz cloud p2p, the same did not activate at all. Whenever I tried to activate and put the serial number of the NVR it said that the NVR was off or that it did not exist, so when I clicked on custons and added the address dev.sa.ezviz7.com it activated OK. Out of curiosity I deactivated the address and tried again and to my surprise continued to work, which seemed to be necessary to force the operation by putting this address. There, I left the google DNS configured (8.8.8.8 / 8.8.4.4), because I was in doubt if the problem could not be the DNS that did not find the cloud, but I did not return the previous DNS to take a new test .
Many thanks to all and much success!