Mohela Balance Increased on SAVE forbearance

Help, my student loan serviced by Mohela increased the balance by $2400 out of nowhere. Currently in SAVE forbearance and they have not added interest to my balance to date, despite reading that it has been done to others in this sub. I have been taking advantage of this forbearance and making large payments towards my loans. I made a $3800 payment to my loan a week ago and and my account had been reflecting the correct balance up until yesterday after this payment. I logged into my account today to find that the balance has increased by about $2400 overnight and I can't seem to figure out where this came from? It's very disheartening. I tried to call customer service but it was a several hour wait. I ended up sending an email through the message portal but don't have high hopes for that. Would appreciate any input on this, has this happened to anyone else recently?