today on apex.oracle.com in my workspace where one 2 apps are installed right now, IG Cookbooks V6 and Sample Interactive Grids.
now i access Gallery option on top and first install Apex PWA App, when installed then click Brookstrut Sample App's Install button, after installing both i go to App Builder and surprised because there was no PWA App but Brookstrut on the list… again i access Gallery and installed PWA App after installation complete go to App Builder and surprised again… now there is PWA App and no Brookstrut?
is it a some kind of problem or i can have only one from these two?

notice that Install button of Brookstrut App is ready to install and PWA App showing Edit and Run buttons.
regards
note: now when i installed Data Loading sample app the PWA App has gone.