Storefront API unexpected search results

[rohantaneja-dh]

Hi, I'm using the Storefront API to fetch products for a particular vendor from my store. I have a few vendors whose names start with "Devpack" and one vendor who is named just "Devpack".

All these names being:
"Devpack"
"Devpack A"
"Devpack A B"
"Devpack B"
"Devpack_C" (Yes it's an underscore instead of a space)

As visible in the screenshot, these vendors have the following products respectively:
"Bananas"
"Bananas A"
"Bananas A B"
"Bananas B"
"Bananas C"

Context:

When I search for the first 100 products with vendor "Devpack", I get the correct results:

// GraphQL Query

query {
	products(first: 100, query:"vendor:'Devpack'") {
		edges {
			node {
				title
			}
		}
	}
}

// Response

{
    "data": {
        "products": {
            "edges": [
                {
                    "node": {
                        "title": "Bananas"
                    }
                }
            ]
        }
    }
}

The issue:

Now, when I want to search for products from the vendor "Devpack" and only those that have the word "Bananas" in their title, I get the following results:

// GraphQL Query

query {
	products(first: 100, query:"vendor:'Devpack' title:*Bananas*") {
		edges {
			node {
				title
            }
		}
	}
}

// Response

{
    "data": {
        "products": {
            "edges": [
                {
                    "node": {
                        "title": "Bananas B"
                    }
                },
                {
                    "node": {
                        "title": "Bananas A"
                    }
                },
                {
                    "node": {
                        "title": "Bananas"
                    }
                },
                {
                    "node": {
                        "title": "Bananas A B"
                    }
                }
            ]
        }
    }
}

1. Observe that I now get results from all vendors that "contain" the word "Devpack" instead of exactly matching "Devpack". This happens as shown above when I append title=*Bananas* to the query.
2. Also, only products from vendors which have the exact word "Devpack" in their vendor name show up. Notice that "Bananas C" from vendor "Devpack_C" doesn't show up as expected.

Expected Behaviour:

I would expect Shopify to only return "Bananas" from vendor "Devpack" when my query is "vendor:'Devpack' title=*Bananas*" and not from all vendors that contain the exact word "Devpack" such as "Devpack A", "Devpack B" and "Devpack A B".

As per the documentation here, "vendor:'Devpack' title=*Bananas*" is the same as"vendor:'Devpack' AND title=*Bananas*" so I'm guessing that's not the issue here. I've confirmed this by adding an "AND" in my query and I get the same results.

For now, my solution is to never have spaces in my vendor names and always use underscores. But I'm not sure if this is a failproof solution and the right approach. Please let me know. 

Thank you.