Setting up an audit trail in Odoo for Bill of Materials (BOM) can be a bit tricky. From wht you've described, looks like you've taken some good initial steps. Just make sure to double-check the model name in the audit rule; that’s gotta be correctly linked to the specific BOM object you’re trying to track. Odoo can be oddly particular about these small details.

Hey, also check out the user's access rights cuz sometimes the problem is just a permission setting you missed. Believe it or not, that's a common hiccup. Don’t forget to see if your system’s got some caching enabled - sometimes the cache is why a change doesn’t show up right away.

If you're running custom code or third-party modules, they might be messing with the standard Odoo logging mechanism. Turn on developer mode, it might uncover hidden settings or tools. I remember I had to fiddle with it once.

Finally, this might sound basic, but are your log points activated across all environments? Testing in dev or staging can give different results if configs aren’t consistent. If it still doesn't work, reaching out to an Odoo expert might be worth it. Good luck!