I mean what is the new IP you trying to set when you click save. But if you only click save not save & apply then the ip should still 192.168.0.99.
But then i am confuse, how did you connect to the internet? You should had modem, and router if had several PC ?
I was trying to set 192.168.0.30.
The plan was, that the router connects to my internet wifi router as client.
I wasn't connected to internet while i was setting up the tp-link, all local and I downloaded the firmware image before.