Dear Sajeev,
Thanks for your confirmation and I can reproduce the issue in our environment.
As you set the uploaded file as draft and the file status is pending, I'm afraid that the reviewer (The Visitor group) can't see the file and can't approve it. This is forced by the Require content approval for submitted items feature.
I'm afraid that there is no way changing this. The feature is also configured with an internal flow which is also conflicted with the custom approval flow you created. The custom approval flow's result will change the values of the column deployed by the Require content approval for submitted items feature.
To avoid the issues between the custom approval flow and the flow triggered by the Require content approval for submitted items feature, I suggest you turn off the Require content approval for submitted items feature and only use the custom approval to achieve all your requirements.
You can create a library to set the files' status and save the approved files and create another library for reviewers to access to review the pending files.
The flow example is like the following.
Thanks for your understanding and have a nice day!
Cliff