Firestore read and update is taking 1-12 sec delay to complete in Python

I am using firebase python client to write data to firestore.Any read / write operation at least takes 1 second to complete.Firestore DB is in us-central and our server is in Singapore. Is it what causing issues? During read, I have used a where query with limit like below.

collection_ref.where(
            u"field", u"==", u"field_value").limit(1).get()

During write, I use set and update(dict)

Sometimes the lag is around 10 to 12 sec

Did anyone face similar issues?

Any pointers will be appreciated