Looking for an ASO Expert for Android App

We have a couple of apps. For those apps, we did ASO and running Admob Campaign but didn't get a good result. In 1/2 country for a couple of keywords the app showing at the top but didn't getting a good amount of organic install because for all other countries those keywords aren't ranked. Even App title and short description keywords didn't get ranked.

We don't know where is the fault. For our most of the apps have similar kinds of issues.
We are looking for an ASO or App Marketer who will sort out the issue and rank our app for valuable keywords for most of the country where we will get a massive organic download.