Read File with append

[lockedude]

I am attempting to use the Read File action to create a new named temporary macro (not the default name) with the entire contents of simple multi-line text file.

Line A
Line B

Then I am trying the Read File action with a different multi-line text file and Append (check box checked) the entire contents to the previously created named temporary macro. Let's say the second file is like:

Line C
Line D

The resulting temporary macro is:

Line A
Line B
Line A
Line B
Line C
Line D

Am I missing the meaning behind the append, or is something not right? I would expect:

Line A
Line B
Line C
Line D

I am using v9.5. Thanks!