Given a dataform with duration field and a formula that divides the field seconds value by 3600.
Add a new entry. The entry form display the formula instead of nothing or 0.
This can be solved by replacing empty content with 0 when processing the formula.
Another problem is with the [[entryid]] pattern that is not resolved in new entries. When this pattern is used for a formula id so as to aggregate in the entry level, the calculation fails and the formula is shown.
A temporary and hacky solution for this problem is to remove unresolved [[entryid]] patterns before processing the calculation.