CRM 2016 Online OnChange Event Not triggering the Javascript function when changing the field value from Custom Ribbon.

Hi Team,

I have added a Custom Ribbon Button on the CRM form which updates the OptionSet Value of a field on the form.

The field is getting updated but the OnChange Event Registered on the the field is not getting triggered.  And also if i click the Ribbon Button next time, its  getting corrupted in the second time.  I guess these is some problem with the OnChange Event in CRM 2016 Online. 

Are you guess having the same issue ?