Hi there i have exactly the same problem. When create a new app in app center it is ok to publish and make a certificate, but when i want to update it thrue publish/ create app packages it will show error in end of the build: The "RemoveDisposableSigningCertificate" task was not given a value for the required parameter "CertificateThumbprint".
Now my situation is that i cant update my apps in microsoft store i dont know how to fix it. I tried visual studio 2019 but it looks like it doesnt show my apps it doesnt cooperate with parner center.
have you any ideas how to fix this? thank you...