Before trying anything else, check your DHCP setting in your router and make sure that the static IP you are wanting to use is not in the DHCP range e.g. 192.168.10.10 through 192.168.253 . If so raise the starting number to say 26 or decrease the end down to 199.
I always reserve at least the first 25 IPs for Servers, Routers and such in the first set. Alarms, Cameras, Printers, and Phones in the last range set.
If its getting a MAC then there is a device getting that IP address. Find the conflicting device and do a ipconfig /release and /renew to force it to get a new IP after making your changes.