Selecting multiple items in Photos does not work

Describe the bug
When running Bettertouchtool I cannot select multiple photos in the Apple photos app on macOs Mojave. Dragging selects the photos in the selection rectangle as expected, but CMD-Click selects only the current selected photo and Shift-Click selects only the current selected photo.

When I quit BTT selection works as expected with both CMD-Click and Shift-Click selecting multiple photos.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
MacBook Pro 2018 Trackpad and multiple Magic mouses and Trackpad 1st gen.

If applicable, add screenshots to help explain your problem. (You can just paste or drag them here)

Device information:

  • Type of Mac: MacBook Pro 2018
  • macOS version: All versions of Mojave since the 3rd beta including stable versions
  • BetterTouchTool version: All versions (stable and alpha) since about 2 months, current 2646 (956)

Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.):

Note: Before bug reporting, please make sure you have the latest version of BetterTouchTool and that you have already tried to restart your system :-). If you encounter a crash, please attach a crash log from the macOS from the "User Diagnostic Reports" section.