"Perhaps there is some type of router setting filtering the use of numbers below 100 or 200"
What?? No, and No.
Lets say the router had some firewall rule it that said hey if your IP is not between .100 and .200 you can not use the internet.. Sure lets say He created such a rule without knowing it.
The problem is this statement
" I redo it and validate settings and what it does is just make it dynamic again, What am I doing wrong? "
Sorry, but the system does not auto change back to dhcp - it just not, not matter what settings you might put on a firewall/router its connected to.. It just not possible - no way no how. You could even put in a duplicate IP of even say your routers IP in as static.. Its not going to change it back to dynamic
Set my IP to same as my gateway.. Still took it, now it warns me when it detects dupe -- but it never changes it to dhcp again. Now what it does is say hey that address is duplicated, lets try a APIPA address, ie random 168.254.. So when you click ok on the error it changes it to that.
But look here - my settings are still there as static.
What is more likely is the OP was doing something wrong, maybe not elevated to admin and tried to change the IP? And then he did elevate up when setting it to .200
Not sure what the user was doing wrong -- but I would bet my left nut it has nothing to do with any router filtering anything