Me too. As a work-around, you can install from the command line. See the following SO post which uses xcode-install and xcversion:
https://stackoverflow.com/questions/34493934/how-to-install-ios-simulators-from-command-line
I used :
gem install xcode-install
xcversion simulators --install='iOS 13.2'
Once downloaded and installed, all the simulators will appear in Xcode.