First, I'd recommend checking that you're exporting with the latest version of in5, version 3.8.11.
Then check that there isn't a white screen in your exported OAM content.
If you're still having trouble, I'd be happy to take a look at your InDesign package (File > Package...). You can send it to us here:
I'm so glad you figured it out.
That's a good point. If an OAM file is dependent on the Flash Player (as it would be if the new Animate document is created with the Platform Type set to Actionscript 3.0), then it likely won't work now as Adobe ended support for the Flash Player in 2021 and many browsers had already dropped it.
For anyone with the same issue, you can convert your Animate document to Canvas by going to File > Convert To > HTML5 Canvas.