Hi there! I had the same problem and could not get any help from calling support.
When I completed filing my 2020 tax returns this year, no PA signature page was included. The "Electronic Filling Instructions ..." Page was not included in my documents to print this year. So I looked back at mine from 2019 and the second section down on that sheet says "No Signature Document Needed" ..."No signature form is required since you signed your return electronically."
So I think as long as you used the e-signature when you did your e-filing, it counts for the state and you do not need to send in a separate paper/snail mail signature.
Hope that helps!
