According to the documentation:
https://docs.splunk.com/Documentation/DBX/3.1.1/DeployDBX/Prerequisites
For 3.1.1:
Splunk Enterprise
This version of Splunk DB Connect is compatible with Splunk Platform versions 6.4.0 and later.
So yes, however, looking at the release notes there are numerous fixes, some of them specific to 7.0 and 7.2 which are addressed in later versions.
3.1.4 is the latest DBX, so you may want to consider testing and upgrading to that to avoid such issues
If my comment helps, please give it a thumbs up!
