First you can check the field by putting the code and calling it on save event:-
function checkFieldOnSave() {
var attributes = Xrm.Page.data.entity.attributes.get();
for (var i in attributes) {
var attribute = attributes[i];
if (attribute.getIsDirty())
alert("attribute dirty: " + attribute.getName());
}
}
Then you can resolve the issue. If you are still unable to resolve then put this code and call it from on save event:-
function onSave() {
Xrm.Page.data.entity.save();
}
Regards Faisal