If you encounter a 400 Bad Request error while connecting to Amazon S3, and the log displays:
The [region] location constraint is incompatible for the region-specific endpoint this request
was sent to
you are likely attempting to access a bucket in a region created after March 20, 2019. In such cases, S3 returns a “Bad Request error” if the request does not arrive from the correct region endpoint. To resolve this, configure the accurate region ID in the S3 tab of your site.