Unbroken and Unfluctuating

Unbroken adjective - Going on and on without any interruptions.

Unfluctuating and unbroken are semantically related In some cases you can use "Unfluctuating" instead an adjective "Unbroken".

Unfluctuating adjective - Not liable to fluctuate or especially to fall.

Unbroken and unfluctuating are semantically related in steady topic. Sometimes you can use "Unbroken" instead an adjective "Unfluctuating", if it concerns topics such as smooth, fixed, even, flat.