Can queries that users ORDER BY using date to sort data be non deterministic?
If the date you are sorting by has repeat values in it and are not sorting by any other columns the order you get them in will be arbitrary.

Result set 1  

email|date
aaa@gmail.com|2019-01-01
bbb@gmail.com|2019-01-01
ccc@gmail.com|2019-01-01


Result set 2

email|date
ccc@gmail.com|2019-01-01
bbb@gmail.com|2019-01-01
aaa@gmail.com|2019-01-01


If you just have an order by on date the database can return either result set as is just ordering by the date field and pulling in records as it gets them regardless of order.

If you need a consistent order in the results you are going to need to add more fields to the order until you can get a more unique set of fields to order by.

For your query I would update it to also order by _id so you will have a consistent result set

SELECT id AS "_id", 
       cpf, 
       email, 
       name, 
       agency, 
       account, 
       "createdDate" 
FROM "NextUsers", 
     "Users" 
WHERE "userId"="Users".id 
ORDER BY "createdDate",
         id 
OFFSET $1 
LIMIT 500;