Unable to connect to any dbs in locally hosted Retool, ECONNREFUSED

I'm looking for some tips / steps to troubleshoot being unable to connect to any databases from a locally hosted Retool instance. I have several databases in the cloud that I'm normally able to connect to via other tools without any issue. I see "Unable to connect. Error: request to http://db-connector:3002/api/testConnection failed, reason: connect ECONNREFUSED" no matter which database I try (e.g. MongoDB using an SSH tunnel, MySQL standard connection).

I notice a few things in the docker logs that seem to suggest the containers are flapping but I'm not sure if they are meaningful or not. I see these repeating frequently, maybe once a minute or so, and am wondering if these provide any clue:

retool-onpremise_db-connector_1 exited with code 137
retool-onpremise_db-ssh-connector_1 exited with code 137

Thanks in advance