Plex plugin messes with ip address

[banana99ou]

I set the ip address to 192.168.45.2 from 192.168.45.104
then following this tutorial https://www.youtube.com/watch?v=looBzNEtjDQ&t=323s
i have installed plex plugin
started plugin. web ui loses connection. fuss around a bit, give it a reboot check lan cable.
typed 192.168.45.104 web ui is there and plex is working
changes ip adress again cannot play movie in plex

sorry for bad english not english user
super duper bigginer