The formula in column F refers to a named range GlucoseFactor. There are in fact 2 such named ranges, one Workbook-scoped and one Sheet-scoped. One refers to:
='Glucose Factor'!$A$2:$B$29
the other to:
='Glucose Factor'!$A$2:$B$32
I suggest you change the formula to:
=IF([@Libre]=0,[@Blood], IF([@Libre]>0,[@Libre]*VLOOKUP([@Date],Table4,2),0))
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