I tried everything you explained and nothing unusual happened (nothing highlighted).

If you copy paste the entire sheet to another sheet or workbook, does the behavior still occur?

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Hmmm

That is perplexing as I did try what you had suggested and the "new" sheet did the same thing that had occurred on the "old" sheet.

I will start from scratch. Hopefully, that will work.

Interestingly, I have developed three other separate spreadsheets and they all worked as intended. Did not have any "extra" cells highlighted when I went to copy/paste one cell to other cells.

Appreciate your assistance.