Recurring severe mouth ulcers and MGUS

Hi there, diagnosed with MGUS a couple of years ago. I get recurring, multiple and severe mouth ulcers. Due for a follow-up with haematologist end -Oct but in desperation saw a new GP who (surprisingly knew exactly what MGUS is) believes there's causation between MGUS and the ulcers (deficient immune response). To be honest I was quite relieved that there was some explanation!! The current bout of ulcers has lasted 5weeks and counting.... Am awaiting GP-requested blood test results to check zinc, vit b, magnesium, iron etc. Also feel fatigued during these outbreaks. Anyone else experienced this?