Extremely frustrating issue that my old cheapo DLink router never had issues with, but I've noticed on a number of occasions that despite assigning a specific IP address to a given device, the router will sometimes issue a different IP, even though the specified IP isn't being used by another device.

The issue happened with 2 wired POE cams, I had setup specific IP assignments for both, and it worked for a while, however after rebooting the controller I noticed it had issued different IPs. I verified that the IP assignment config was still there, and it was, yet the router seems to ignore that and sometimes issue a random IP different than what I had told it to use for that device. Rebooting the camera fixes the issue but I'm worried that these rules aren't respected by the router at times and that it's non-deterministic.

Of course I can setup each camera to use a static IP but I always want to avoid devices setting their own static IP at all cost and I've had no problem with other routers.

Am I doing something wrong? Have others seen these types of issues?