Same problem, I tried solution in https://kb.parallels.com/en/129255 It did not work. I have to downgrade to Version 20 to solve the problem
Hello, Please note that this is a known issue and it is currently being investigated by our Development team. As a workaround, we would recommend to downgrade to Parallels Desktop 26.0.1 using this link. Note: When prompted to update to the latest version, kindly do not update to latest build and use current version. You may subscribe to this KB Article to be notified once a fix is released. Thank you!