Here are the following reasons which might lead to the suspension of your account.
Getting Paid Outside The Upwork Platform Sending Copy And Paste Proposals Sending Many Proposals And Not Getting Hired Poor Feedback From Clients Harassing Clients To Change Your Feedback Or Give You 5-star Feedback
Had you done any of these?
I apologise for the delay. I'm checking your account with the team, and I'll come back here once I have more information about your account.
ETA: Hi Destiny, I'm coming back here to inform you that the hold on your account has already been lifted. I apologise if this has caused any inconvenience on your end.