Agreeing with V.V. that although "un" is typical negative, many times "unwavering" is used positively.
I would even say that those in the U.S. think of and use this word mostly in a positive manner, meaning the person is determined and won't let anyone or anything deter him/her from their goal.
Some common uses are...
She is unwavering in her faith.
(meaning she will not let anything pull her away from God)
I'm sorry, but I cannot do what you're asking. This is unethical. I will not waver in my decision.
(here we use "will not waiver")
However, when we want something that someone is not giving us, we could use the word in a negative context.
- COWORKER 1: My manager is very tight with the budget and will not let me purchase a second monitor. COWORKER 2: Have you tried telling her how much more productive you will be? COWORKER 1: Yes, but she is unwavering in her decision. I'm wasn't able to change her mind.
I hope this helps!