Maxcut hanging when using Shift Select and CTR X or V on large list of items

Good day

When using the following Window short cut features, Shift Select, Ctrl C and/or V, in the “Input Items” window on large lists of items (267 items) causes the program to hang indefinitely or for many many seconds. Then the only way to stop the process is to hit the programs close window (red X button) which crashes Maxcut.

If I attempt to delete smaller chuncks of the list then, although still slow to complete the task, the program does not hang.