The IP address has nothing to do with Ignition - that’s windows and networking. To put it simply:
The 3rd digit of the IP addresses need to match for the devices to talk. Your router uses 1 (to provide Internet access) and your PLC uses 100. Those schemes don’t jive. Decide if you want to use 1 or 100 for your PC.
There are lots of work-arounds, but that’s your fundamental issue.