Consider a numeric field with n decimal places where the value in this field is calculated via a default formula.
If the formula returns a value with > n significant decimal places, TeamDesk stores the value up to its internal limit of 6 decimal places and displays ONLY n decimal places BUT NOT ROUNDED to these n decimal places. Explicit rounding can be used as a workaround.
A similar situation occurs with numeric formula fields.
TeamDesk support have advised that this is a bug and that a fix will be forthcoming. I raise this as a forum topic to create a public reference number for this case.