input param on service comes in as <param>List

I have a service, which takes a stringList as an input param (“keys”). When I invoke it through a browser url with http://host:port/invoke/serviceName?keys=a,keys=b
I see both a, b in the input param as I expect.

However, for other similar services, when I restorePipeline, I see that they come in with input param name keysList (populated appropriately). However, since my code is referring to keys, it fails. Has anyone seen this strange behavior. I have the latest flow fix on 7.1.2. Any help is appreciated.