Panel output = A String (text). The text 1 = the text 1 that you are testing against.
The output of absolute value reads as 1 but is likely some floating point number behind the scenes. The issue here is tolerance vs decimal display. You should test in this case if Abs|A-B| < tolerance (it is good practice to always do that anyway, in scripting as well)
The real culprit here in tricking you is this option in File > Preferences > Display called “Special Case Integers” which you may want to turn off.
https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html