I had the same problem with food, my taste buds finally came back after about two years, it’s the steroids that affected my taste buds. Told my doctor I didn’t like them, my weight loss was down to 170 lbs, the doctor ordered a pill that helped me put on weight back to 190lbs. After five years I finally that I am in remission for two months so far. Feeling wonderful now, no problems!

Victor;I am not on treatment, haven't been for almost 4 yrs. Experience has taught me that oncology is separate from other issues. Even if it may be a side effect of MM/treatment. My primary deals with and refers me to whatever dept. His thinks can help. Lately I'm waiting for an MRI of my head/brain.Radiology..or insurance has not
approved of an MRI yet. I did have a CT Scan and he thinks I should further it with the MRI. I hope it isn't turned down. The specialist would mean better insurance coverage. I am not complaining.It is what it is

Are you still on active treatment? One of the agents you are on may be causing this.
The other thing I cautiously suggest is testing for Covid as it is still around and also causes loss of taste and smell even if you don’t think you are experiencing other symptoms.

I would highly suggest that you get a Myeloma Specialist, especially if you are not getting the results you feel you should from your current doctor.
Unfortunately if you are seeing an oncologist, many only concentrate on killing the cancer and are not concerned with side effects or other issues that may arise.

I hope your taste returns. Mine did but it has changed, in such that somethings are not so appealing as they used to be; like dark chocolate.