The same happened to me and I have 5 stars ratings on all sales, the only impact I could have is missing (by accident) some self imposed deadlines that the customer did not even know about.
I was getting enquiries daily now is completely dead.
I am in datascience and I used to get daily enquiries, this was until mid Janurary and suddenly just completely stopped, I kept the account in good order and I have positive FB from the buyer, what is going on?😀