I also have a inner ear problem and I have had several autoimmune problems. mine are Graves Disease, RSD, Asthma, Celiac Disease?, Osteoporosis and low iron levels. i had not thought about either AIED or low B12 symptoms. My B12 ws ok last time I checked.
But this is food for thought and considering the other problems with inflammatory problems, it might be the cause. One other cause of lack of balance is dehydration. Now that is something I can relate to as I often forget to drink water.