Sure, Slash is the fully managed DBaaS. Set yourself up with a free Slash Account: https://slash.dgraph.io/
You can deploy up to three instances on the free tier with a total monthly credit allowance of 10K.
This guide will walk you through any details you might need.
If I were you, I would setup two backends both on Slash and then setup a custom query from one to the other. Load in a few sample nodes of data and duplicate the problem. Once duplicated, open up a ticket on slash for support and they should be able to get into the logs to see what exactly is going on to pinpoint the bug and the fix.
@gja is your man for Slash support here on Discuss!