Selecting Code with latest Rstudio

I just installed Rstudio v 1.2.1225 and I cannot select code. I can select code with my old version 1.2.1114. I am using a MacBook Pro with the MacOS v 10.14.5

Can you try changing the editor theme to some other theme, and then back again? There was an issue affecting some users of the RStudio preview where an issue of this form could occur.