Websites hanging AP mode XE75 pro

EDIT – i have now fixed the issue , somehow the decos reverted back to router mode , changed it back to AP and now working fine again.

I recently bought a TP-Link Deco XE75 mesh system and have set it up in Access Point (AP) mode.

I need to keep my Sky router in place because my VoIP phone service relies on it, so I can't connect the Deco directly to the ONT permanently. I've disabled Wi-Fi on the Sky router and I'm using the Deco system for all wireless connectivity, with wireless backhaul between the Deco units.

The setup is essentially:

ONT → Sky Router → Main Deco XE75 → Wireless backhaul → Other Deco units

The problem I'm experiencing is that websites will sometimes hang for several seconds before they start loading, and occasionally they time out altogether.

As a test, I connected the Deco directly to the ONT, bypassing the Sky router, and the problem disappeared — websites loaded immediately and I didn't experience the hanging/timeouts.

This makes me think the issue is somewhere between the Sky router and the Deco rather than with the Deco Wi-Fi itself.

Has anyone experienced something similar with a Sky router and Deco XE75 in AP mode? Are there any Sky router settings, DNS/IPv6 settings, MTU issues, or other configuration changes I should try?

Ideally, I'd like to keep the Sky router handling the internet connection and VoIP, with Wi-Fi disabled, while using the Deco XE75 system purely for Wi-Fi/mesh.

Thanks.

Edit i have tried changing DNS on laptop to google and cloud flaure still get the issue , also sometimes pages say "hmm cant reach this page" then it loads after that error.