KDE "choose directory" dialog only open directory but not choosing them


I am trying to package TeleSculptor.
I package the binary of TeleSculptor.
TeleSculptor binary from upstream was build with Qt 5.11, but for Flatpak, I use KDE Sdk 5.15.

I tried using the app.
I click file>New Project, and I suppose to choose the directory where I want it to be save.

The “Select Project Directory” dialog open, but when click “open”, it just open the folder without choosing it. I cannot choose a directory.

I tried giving it --filesystem=host and home, still does not work.

Now, when I try running TeleSculptor without Flatpak, just the binary provide by upsteam, I got this, which I can choose directory.