AP (no DHCP server) serving IP's while main router (DHCP server) is not available?

(For some reason, the OP won't simply do this; nor any thing else that could easily identify the specific device...and won't explain why.)

e.g. A Windows PC/laptop clearly displays the identity of the DHCP server that issued the IP when running commands/buttons to show the network information

Edit: also the OP claims I gave some word. That is clearly untrue; and in good conscience, I wouldn't stand by while others' valuable time is wasted repeating the same troubleshooting suggestions they refuse to attempt. Others can choose to continue assisting, the same as before this post.