Take a look at the hidden columns beyond column I.
There are two equations that use “sort” - they are in cells K3 and R3.
Those equations end with the sort priority:
2, true, 4, true, 3, true
Where:
2 = Group
3 = Account
4 = Last Updated
5 = Balance
And:
true = ascending
So, the accounts are sorted by Group, then Last Updated, then Account, all ascending. Last Updated is what makes the order appear random.
If you want to sort by Account, then change both cells equations to:
2, true, 3, true, 4, true
which just swaps Account and Last Updated, so they’re sorted by Account first.
Or by Balance:
2, true, 5, false, 3, true