Zoho Mail - Unable to Connect with Server

Zoho Mail - Unable to Connect with Server

Hello,

I keep getting the message 'Unable to reach the server. Please check your network connections', this started today suddenly.

I have tried:
-Multiple Browsers
-Other devices
-Resetting router

Strangely, if you leave the window open, new emails will be listed but you won't be able to read them. If you open the new email in a new window you can then read the email but only emails that have arrived recently.