The shipping information was unable to be saved code example

Example: unable to save shipping information. please check input data. magento 2

I've got this issue as well. But in my case it is due to the email validation. If you have a domain with a .cloud extension, and use this for email - e.g. test@test.cloud - you will get the same issue. Changing to a test@test.com and the order proceeds as normal.
https://github.com/magento/magento2/issues/8544