Sorry for not being able to get in touch with you.
I checked your Adobe account and your Export PDF subscription looks all fine to me. Its active, so it shouldn't be asking you to pay again, unless you haven't installed some other app.
1- First you need to check whether you have got Adobe Acrobat Reader DC or Adobe Acrobat DC installed. Your subscription will only work with Acrobat Reader DC. If you have got Acrobat DC, it wont let you to use Export PDF through it. They both looks identical, so don't get confused. Uninstall Acrobat DC (if its there)
2- Make sure you are signed in using correct email address.