Chromecast not connecting anymore

[Smcn01]

I have several Chromecast and a nest mini which now no longer connect successfully to talk talk router.   I've separated the 2.4 and 5g network names a while back but their not connecting now. Nest mini connects but no longer streams any music.  

If I connect to another network or hotspot then they all work fine, so something has changed in TT router. Has a router change or firewall change been applied.  Any suggestions welcome.   Ap isolation is off. 

[Michelle-TalkTalk]

Hi,

I've included a Help Guide below,

Restore your router to factory settings - TalkTalk Help & Support

Thanks

[Smcn01]

I've reviewed it but not factory reset it.   Can you advise how I do this.  It's a few years old and noticeably getting slower so it may resolve that aswell.

[Michelle-TalkTalk]

Morning,

I'm sorry to hear this. Have you tried factory resetting the router and then re-setting it back up again?

Thanks