Your wiring is right.

Not sure why the dimmers are acting up, but I suspect they're the trouble.

To troubleshoot, I'd go back to dead-nuts basic: incandescent bulbs and rheostat dimmers, then start adding back your desired components.

As someone else mentioned, many dimmers are electronic now, and many of them require a neutral. Since your setup does not have a neutral at the switch, look for dimmers that say right on the package that they don't need a neutral. Rheostat ones don't of course. Also, LED lights have a driver circuit in them that does not always play nice with some dimmers.