I suspect my combobox giving error while click on button cancel.
So far it works fine during submit, update data to sharepoint except cancel.

Shrepoint :
ReguStatus
Multiple lines of text
Button Cancel:
If(IsBlank(DataCardValue94_1.Text),
Notify("Pls enter remarks for cancellation in Audit trail section",NotificationType.Error),
Set(Action,"Cancelreq"); - powerautomate update status as cancelled
SubmitForm(Form2_1))
ReguStatus
Item:
SortByColumns( Filter( PR_Configuration, Lower(LookupKey2) = Lower("ProdRegulatory" & txtcmpny.Text) ),
"SortItem", Ascending)
Default :
Update: Concat(ComboBox2.SelectedItems, ItemDetails, ",")
DefaultSelectedItems:
RenameColumns(Filter(Split(Parent.Default, ";"), !IsBlank(Result)), "Result", "Value")