Urgent: InMobi SDK setup help!

I am seriously at my wit's end trying to get InMobi SDK integrated into my new Android game, it's been two full days of pure frustration and I feel like I'm hitting a brick wall. Nothing, and I mean absolutely nothing, seems to be working. I'm developing in Android Studio using Kotlin and my goal is to implement InMobi interstitial video ads to monetize the game, but I can't even get a test ad to show up. I’ve meticulously followed the official InMobi Android SDK integration guide, going through every single step multiple times, thinking I must have missed something obvious. I've added all the required dependencies to my app's `build.gradle` file, made sure the SDK is initialized correctly in my `Application` class with the proper Account ID, and double-checked that I’m using the correct Placement ID for the interstitial ad unit. My `AndroidManifest.xml` has all the necessary permissions and activities listed exactly as specified in their documentation. I've tried running it on multiple test devices, including a physical phone and an emulator, but the result is always the same: no ads load. The `onAdLoadFailed` callback is consistently triggered, often returning `InMobiAdRequestStatus.NO_FILL` or sometimes `INTERNAL_ERROR`, but without any specific crash logs or detailed error messages that could point me to the root cause. Occasionally, I'll just get a blank screen where the ad should be, which is almost more infuriating because it's so vague. I've scoured InMobi's own documentation, their forums, and even Stack Overflow for similar issues, but haven't found a solution that works for my scenario. All I want is for *any* ad, even a test ad, to load successfully so I can confirm the basic integration is working before I move on to more complex implementations. Has anyone here faced similar issues with InMobi SDK setup, particularly with `inmobi interstitial` ads on Android? Are there any obscure steps or common pitfalls that aren't clearly documented that I might be missing? I am desperate for any working code snippets, debugging tips, or even just a pointer in the right direction.