Copy and Paste / Values - from General to General / a word vs. a CONCATENATE formula

I'm running into an issue copying data from a concatenate formula in one worksheet, to another worksheet, within the same file.

If it's just a word, things work fine - I hit the:
Enter key: I have to hit it twice - It pastes as expected
Arrow: I have to hit it once - It pastes as expected

If it's from a formula that CONCATENATES words, however, like:
=CONCATENATE(AZ3, " ... ", L3, ", ", M3, ", ", N3, ", ", O3, " ", P3)
You initially see the Values, but when you hit the:
Enter key: I have to hit it twice - The first time you see . . . #REF! . . . Then it goes out of the cell, and #REF! remains
Arrow: I have to hit it once - It pastes as expected

The reason I'm asking about this is that I don't think it used to do that with concatenated words and the Enter key. It used to paste as expected.

I think I changed something, but don't know what . . . Any ideas?