Our extension is currently not compatible with the Text > Single line text > List of values Shopify metafield content type. This compatibility issue will be fixed in a future release.
To index multiple values from your metafields to Algolia you can use the Single line text > One value content type:
Single line text > One value
Then, you would need to set the type conversion on the Algolia App for this metafield to String Array:
Algolia Search and Discovery > Indexing > Metafields indexing
Finally the values for this metafield on your products should be separated by a comma (,)
If you have set this metafield as a facet, this should be the output: