Data paste is grouping worksheets together

[Tristram_ZX81]

For some reason when I paste the data into columns A-E (image 1) it's grouping the Shifts and TC Effort worksheets into one, removing the ability for me to undo last action, and also wiping data from the corresponding A4 to E4 and down on the TXEffort worksheet (image 2). Any idea why? I've tried unmerging cells, which is a common suggestion to this problem. Also worth noting that the worksheets are *not* merged at the point of pasting, but are immediately after. Please advise, this problem is driving me mad!

 

[jkpieterse]

There are no macros that get triggered by control+v by any chance?

 

[Tristram_ZX81]

Fixed this now. I ungrouped the sheets before I pasted, even though they weren't visibly grouped anyway.