Here is simple script - Photoshop2018selectDialogBug.js with just a one line of code:
Folder.selectDialog("Please select folder to process");
As you can see on screenshot “Photoshop CC 2018 selectDialog.png” latest Photoshop CC 2018 19.1.0 popups wrong folder select dialog window. In previous Photoshop versions (e.g. CC 2017 or even CC 2018 19.0.0) it shows right dialog window - “Photoshop CC 2017 selectDialog.png”. In new selectDialog window there are no prompt string that was passed to the function: “Please select folder to process”.
This issue is also occur with Folder object method selectDlg()