Certain websites and apps not working - okay on some devices but not others

[Iolaire]

I have the Fibre 500 package for well over a year now. It seems to work fine on some devices but on others certain apps and sites don't load or work. 

On my laptop everything seems to work okay, but on my phone the banking app doesn't work. My housemate has more trouble - he cannot access lots of websites on his computer such as BBC iplayer and can barely use the wifi on his phone at all.

[Michelle-TalkTalk]

Morning,

Do you see any specific error messages when you can't access these sites? Have you tried powering down the router for a full 30 minutes and then retested again as this will clear the current session?

Thanks

Michelle