There can be a few reasons why your animation is stuck on rendering, here are a few things that you can check:
1. Check the size of your animation, large file size tends to have a longer rendering time. If your file is more than 1MB, give it a couple of minutes to wait until the render to complete.
2. Your animation contains any unsupported features that may cause the render to fail.
Check out this page to see the list of the supported and unsupported features.
3. If none of the above is in your case, then make sure to check if your animation consists of any track matte. There is a known issue with AE 23 track mattes and Lottie as this prevents Lottie from rendering.
However, there is a workaround to export Lottie files with track mattes using the old method following these steps:
1. Use a track matte layer for every layer you want to matte
2. Keep the track matte layer on top of the layer you want to apply the matte.
For more information and tips on how to work around this issue, check out this reels video created by one of our Motion Designers: https://www.instagram.com/reel/Cn3l1xNs5Au/