Expected: Both seed rows render, and a totals row shows Sum 42 under Amount and AVG 21 under Second Amount Display
Summary: The totals row renders but the Sum aggregation is broken. 'Second Amount Display' shows 'Average= 2' (correct: AVG of 1 and 3), but 'Amount' shows 'Count= undefined' instead of 'Sum= 42'. Both seed rows render (probe 10 = Amount 10, probe 32 = Amount 32). The stored aggregation is <FieldRef Name="Amount" Type="Sum" /><FieldRef Name="SecondAmount" Type="AVG" /> (Q3 round-trips), so the mismatch is between stored Type='Sum' and rendered 'Count= undefined' - consistent with the aggregation Type value's case mattering to the classic view renderer ('AVG' uppercase renders, 'Sum' capitalised does not).
Observation: Both seed rows render: 'probe 10' (Amount 10) and 'probe 32' (Amount 32)
Observation: The 'Amount' totals cell shows 'Count= undefined', not 'Sum= 42'
Observation: The 'Second Amount Display' totals cell shows 'Average= 2'
