Onchange events on two add/edit fields in an editable list. How to solve?

I have two views in a K2 SmartForm (automation on premise), where I need to use onchange event for two add/edit fields, but it get me some issues… 
On the Onchange-events, an advanced smo-object method  gets data from an external api, and fill up the add/edit rows in the view.
On the first onchange-event, it gets data for the field, that also have an onchange-event on itself… → When x is filled in - get y, and the opposite, plus other fields.
The events triggers not only once, but several times, and other errors shows, when both the rules is enabled. Someone that have done anything similiar, and have any solution to the problem/-s?
I get problems with how many times the event triggers, and
I get an error, that I can’t find (can’t convert string to timespan..),which should in some way be related to the events , because it disappears, when I just run one of the onchange- events. 
 The - When the view executed List item added , is triggered when user clicks another row…, and a rule on the form is saving the data to database, on it.