Hello,
Adding to Stephane: You should also check if there are no newline/return (invisible characters) entered.
You might see this with cursor position in edit mode (or in Excel with adapted row height and wrap text).
Side note: It seems that you use 999 also as a variable name (see column title). This is not compliant to xlsform.org
“Names have to start with a letter or an underscore. …”
Might this be related with your problem?
