Then you might have none available, the line commitment settings (theres a column on the SO) might say do not commit, your commitment engine might be on a schedule, something might have higher priority.... theres a couple things to check

Is there anyway to check those things? I've tried everything and no results

Have you looked at the reallocate items page for that item? I find it's the easiest way to determine why inventory isn't committing.

No, but I'll try that. Thanks