Reproducing Step:

1. Cut from sheet(A)
2. Paste to another sheet(B)
3. back to sheet(A),

Expected:

• source cell is unmerged
• cutting focus box disappears

Actual:

• the source cell doesn't unmerge
• cutting focus box still exists.
• Moreover, perform unmerge operation on the source cell will not work anymore.

P.S. The reason may be the client side UI update problem, because the merged region is deleted in server side.