Old mutual retirement annuity fund

I have a retirement annuity with old mutual. I have been monitoring my policy with there app. From 50k it dropped to 40k in a few days which is a big drop and unusual. Can anyone explain this too me as I trying to get hold of old mutual main branch but It seems I cant get through. I went in to my branch today but they cant help me . I need answers to why this big drop and how is it possible or is investors wasting or loosing my money. Thank you in advance