When I paste a value from Excel into a text field isnumeric returns false incorrectly. I checked the length of the string, and it is two characters longer than the actual string. I assume some extra characters are being copied, but I cannot see them in the debug window. If I type in the same values the character length is correct, and the isnumeric works. Everything also works if I copy from Excel to notepad, then to a text field. I am working in Windows, and have not tested this on a Mac.
In the debug window, click the magnifying glass icon next to the value and then click into the binary tab to see the raw hex values.
There are two trailing spaces when copying from Excel. I used the trim function, and all is well.