Hi and Welcome to the forum, you might want to have a look at the following FAQ which explains where everything is
Welcome to Benefits and Work ESA reassessments got very backlogged a while ago, to the point where many were pushed back for 2 years. They have resumed now but it could be that your award has been extended, or reassessed purely as a paper exercise. It will remain active until another decision is made, so you don't need to worry about it coming to an end and your money stopping.
I'm afraid the only way you will know what is happening is to phone DWP and ask. Doing so does not run any risk of triggering the process as the people who answer the phones are an entirely separate department.