VirtualBox shortcut in Mac

Describe the bug
Ctrl-Insert (copy), Shift-Insert (paste) mouse button mapped shortcuts are failing inside VirtualBox running LinuxMint. "sudo showkey" in Linux suggests that the sequence of action being activated is "Ctrl down, Ctrl up, Insert down, Insert up" instead of "Ctrl down, Insert down, Insert up, Ctrl up".

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
Normal mouse buttons mapped to Ctrl-Insert and Shift-Insert.

Device information:

  • Type of Mac: MacBook Pro (15-inch, 2016)
  • macOS version: 10.12.6
  • BetterTouchTool version: 2.427

Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.):
VirtualBox is a popular development tool. Earlier versions of BTT used to work with it.