Hi @Expiscornovus ,
I just understood what could be the issue with 'When a pull request is created' trigger.
So, when I turn Off the 'Split On' button in settings, its still failing with Internal Server Error.

But when I turn On the 'Split On' it works, but the problem with this is, it misses some PRs, not sure why, my guess is when multiple PRs are created at around the same time it misses one of them.

Any idea how we can fix this please?