HMRC have confirmed that MTD VAT Return connection issues will require more work before it will be resolved.
They’ve stated they’re working to resolve this issue as soon as possible and expect service to return on the morning of Thursday 18th March.
Until HMRC have resolved the issue, it will not be possible for customers or agents to submit a VAT return through the MTD service. If the situation changes, HMRC will update their status page to reflect those changes.
Please refer to HMRC’s status page for details:https://api-platform-status.production.tax.service.gov.uk/