Black icons in BTT Remote

Describe the bug
The icons appears incorrectly in BTT remote. On a black shadows appears.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
BTT Remote on iPhone


Device information:

  • Type of Mac: iMac 27 Mid 2011
  • macOS version: 11.13.6
  • BetterTouchTool version: 2.427