Update AMPScript functions not working in LINE message

Using journey builder we send both LINE and EMAIL communications on the same journey.

Each contact key has more than one record and we need to send communication to all the records based on unique value (example: Contact Key has 3 records and we need to send 3 communication to them)

We use journey settings entry source as Re-Entry anytime

Our requirement is to update the flag value into the DE field when the user receives the LINE/EMAIL message.

When we use Update Contact Activity its updating based on Contact Key but in our log DE having the more than one record for the Contact Key. So we are updating the value against some unique fields like PET NUMBER (its unique field in the log DE).

When we use the UPDATE AMPscript methods also (updateDE, updateData, UpsertDE and UpsertData). It’s not updating

Scenario 1:
When we use the UPDATE AMPscript method its not updating while sending the consecutive emails.

Scenario2:
UPDATE AMPscript methods are not working in LINE message

So could you please help us with the above two scenarios?

%%[
SET @petNum=[petNum]
SET @updatedDate = Now()
UpdateDE("WelcomeJourney_SendingDE",1,"petNum", @petNum, "WelcomeJourney1", 'true', "coupon1entrydate", @updatedDate)
SET @cuoponCode1_1 = LOOKUP('Test_Pet DB','couponCode1', 'petNum',@petNum)
]%% 
Japan Test LINE POC Content
This is your Coupon Code1.1: %%=v(@cuoponCode1_1)=%%