Hikvision DS-2CD2032-I from AliExpress

Are they UK versions supplied by Exact CCTV?
The 2132F-ISs I got from them were. As were the new 4MP ones they sorted me out with. But best to check with them first I think as I think the 2232s aren't. An NVR I got for my sister was also an NI version.
 
When you change the IP address to one on your local network, are you using the same one each time when you see the problem?
Also - is the address you are changing to one that's within the DHCP address pool of your router?
I'm wondering if you have an address conflict.

If you've been trying the same address each time, maybe try another one, definitely outside those of the DHCP address pool.
I don't see a hardware fault being sensitive to what IP address you use - it's more likely to be a logical problem of some sort.
 
Am I reading this correctly... it seems to work fine as long as it's powered by the 12 volt power supply?
Have you tried a new/different known good Cat 5/6 cable?