I don’t think there is any connection. I saw a recent study out of Dana Farber and Irene Ghobriel where that drug or a similar one turned out to be protective in MGUS patients.
There are many possible reasons your FLC may have gone up including an infection or other inflammatory cause.
The same is true for your back and heart rate. Don’t borrow “trouble.” But it is smart to get everything checked out thoroughly so you feel more relaxed.
I have had MGUS for 23 years and it has been a roller coaster ride. I have a different hematologist now and his “calmness” makes a difference.
Best wishes! You may never progress!