I have got same problem. I used to receive invitations and job regularly with exelent feedback and for the last 2 month all my submittings remain without any reply. I have paid for the account twice already, but situation does not change.
I also try to find what is the problem.
I also never receive invitations last several month.
I'm sorry to hear that. You may read the following articles to help you create an eye-catching proposal, enhance your profile and have an overall success here on Upwork:
Additionally, you may want to read this article to help you learn how to avoid questionable jobs.