For the second time I am having issues with my Paypal connection. 

I run the mac desktop version of Quickbooks and Paypal transactions are failing to download. I get the following error when trying to reconnect using my PayPal login details:

Something unexpected happened and we couldn't connect to your bank.

Try signing in again, and check for typos and other errors. If that doesn't work, try signing in on the Paypal (UK) site. (1)

I can successfully log into Paypal's website using the same details, so this is not the issue.

Last time, this was resolved be me logging into Quickbooks via my browser, however this time, that is giving me the same error. 

Fed up and really need a resolution on this once and for all - any suggestions please?

Edit: I have tried this on desktop version, through Safari and Google Chrome; all give same error