Google Sheets "undefined" and associated issue with APL display

Referring to the Google Sheets “undefined” issue.
In an earlier forum post, the solution was given – to use an IF block with an expression.

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This works and handles the undefined.

But, I noticed, that the variable gets “deleted” from the skill with respect to the APL document. The APL documents that use this variable, fail to display the variable again. All it displays is the variable names, with no value.

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Nothing brings back the variable into the APL document ever, unleess the skill is relaunched. But the speak block seems to hold the variable and speak output works fine.

The only way I was able to get the variable back into display into the APL document was to do a so called “un undefine” or “re-define” or “re-declare” whatever, by putting a dummy value. So if there are multiple variables that become undefined, let us say, we encounter a last row of a Google Sheet, many variables will become undefined. Each of these variables have to be re-declared,

Wondering whether this is the expected behavior or is this a bug?.