Android phone connected but no internet

[#1]

My android phone, Motorola G8 Plus, is connected to my plusnet router but it says there's no internet.
I have gone through all the tech support options with Plusnet.

My phone seems to connect to other WIFI's fine and I've not fiddled with any settings.

Any help would be great.

[#2 · Accepted solution]

Ah Figured it out. My phone was have trouble connected to some WIFI's as well.
I looked under Settings>Network & Internet>Advanced>Private DNS.

My private DNS was set to Private DNS Provider hostname and had nothing in it.
I changed it to Automatic and it started working again. Problem fixed.

[#3]

Moderators Note
This topic has been moved from ADSL Broadband to My Router.