DXC FindSearchProvider - 500 error on Search Index page

Commerce 12.11.0

FindSearchProvider 10.0.2

I had configured FindSearchProvider and until recently this was working in the DXC environments which had "episerver:FindServiceUrl" and "episerver:FindDefaultIndex" in appSettings.

Recently the Catalog search functionality in Commerce Manager stopped working. When navigating to the Administration -> System Settings -> Search Index page on DXC, I get the following error :

I'm puzzled by the error as to why the Indexer is expecting a "connectionStringName" given I'm using the FindSearchProvider.

This is working in my local dev environment with my Find developer index. 

Here's my Mediachase.Search configuration, which was working previously when deployed to DXC.

I've tried various resolutions on the DXC environment i.e. restarting the App service, using my developer index in the appSettings, however without success.

Appreciate any suggestions to resolve this.

Thanks