Just recently diagnosed with MGUS. Since research is my favorite thing, dug into it. And although MGUS is often asymptomatic, it is not always: bone pain seems to be mentioned as a symptom on a variety of authoritative websites -- in fact, sounds a lot like what you are talking about. So yeah -- keep pushing.

In my case, the MGUS diagnosis emerged from a last-ditch set of tests to diagnose my peripheral neuropathy, "last ditch" meaning that if I hadn't pressed hard on avoiding "idiopathic", they would not have done this particular set of tests. So apparently my neurologist who specializes in PN normally doesn't go there, but didn't find it a totally unreasonable thing to check out. And again, you'll find studies demonstrating a high level of correlation, whether or not it's definitely causative.