... read the manual.
I have been playing with Servoy for awhile now and felt confident that I knew what I was doing.
The first time I added a valuelist to a form, it did not work the way I expected.
I was about to post to the forum asking for help, but I decided to look at the manual first.
Lo and behold, there was the answer. The display type for a valuelist can not be TEXT_FIELD.
After changing it to COMBOBOX, it worked perfectly.