I'm developing locally with PayPal sandbox (Test Mode) and Disable Guest Checkout and Show Register/Login Form checked. I've triple-checked that I'm logged out and the register/login forms are not showing on the checkout page. They previously were there in version 18.104.22.168.
The checkout page currently is showing the item with the remove link, the 3 Personal Info fields, and the Complete Purchase button. There is also no small PayPal icon like in the previous version also.