Maybe it's something dumb (hopefully), but after a few updates, when opening Vegas 21 I get the top-half blank, but the bottom-half working. Just in case, I uninstalled v187 and reinstalled v108, also Learning Models 21.1 to 21.0 and it's still the same. Please, let me know if there's a way to get back to the usual setup. What's strange is that I opened Vegas 20 and it works ok.
Screen captures:
https://ibb.co/mcnX3NP
https://ibb.co/X7Tch53