I think I know what's going on here. The first column name is "Column 4 3317" which is not what you should have. There should be just "Column 4". Then you will see a empty value in Mean (SampleValue, 3322).
Please test the following in the table menu "Summary":
Group -> Column 4
Mean -> SampleValue
Subgroup -> TagID
Does that fix your issue?
/****NeverStopLearning****/