Orcale gateway error

Hi

I have a gateway cluster set up, and i am experience issues with oracle connections. The following error appears:  `The provider being used is deprecated: 'System.Data.OracleClient requires Oracle client software version 8.1.7 or greater.`

However we have just going through and upgrade we are currently running:

Oracle is 19c - Client is 19.X

ODAC is 12.2.X

any ideas of what i am missing? 

Thanks

Eloise