Is DHCP not working properly on the router?

Question

DHCP

There is a regular router Sagecom F @ ST 2804, V7. It has the most common standard settings and the DHCP server is turned on by itself, but any connection to the network puts a router, so even the web interface does not work, only a hard reset helps, but if you add all the devices by MAC address and set their IP, then you can work , but what the hell is DHCP then? Here are the settings

Answer 1

distribute DHCP on half the range
192,168,1,101-199

Answer 2

Reset the router to default, configure from scratch to a minimum, update the firmware, reset to default, configure from scratch to a minimum.
If this sequence does not cure, the router is sick. Physically. Throw it out, buy a new one, replace it in the store ....

Answer 3

Perhaps the IP range is 192.168. 1.0 /24 or even 192.168.0.0/16 is used in the ISP's network as a LAN. Accordingly, when you connect the cable to the WAN port, you automatically receive routes and 192.168.1.1 is no longer your router, but some other computer on the network.
Solution: use a different home subnet - 192.168. 0 .1/24 , 10.1.1.1/24 , 172.16.1.1/24 and so on.