VBCS instance refused to connect

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Hi Experts,

I did stage to the app and publish and I got the live URL.

l created sandbox in FA and with structure, page integration.

I added a page with new category with basic role to access the page in FA.

Then, i tried to access the page ...

but, i got gray box when i hover over it. I see the message name of VBCS instance refused to connect.

Any advice please, i need urgent help please 🫣

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