BT Cloud on Microsoft Windows Phone - No data connection message

[CPP1006]

I am moving from Microsoft Onedrive to BT Cloud and all is working fine on my Windows 10 laptop and Android phone.

However when I access BT Cloud on my Microsoft Windows phone I get :

No data connection. Please check your data connection settings and try agian.

I am connected via wifi and Mobile Data is off.... BT Cloud updates (sync) ok but I get the above message every time I access it.

Details are:

Microsoft windows phone lumia 435 running windows 8.1Update

BT Cloud app is 16.3.15.1 (latest to download)

BT Cloud settings:

What to backup - contacts and documents

How - wifi only

When - not active 

I am using 1% of my BT Cloud allocation.

I have tried with Mobile data on but still get the No data connection - this only happens with BT Cloud app.

Any ideas please ?

Chris

[CPP1006]

This morning I uninstalled BT Cloud from my windows phone and reinstalled it again. The No data connection message has disappeared and the folders have syned ok. I will monitor this to see if it happens again.

cheers