GA and firebase session mismatch

Question

We are using two analytics services in our project - google universal analytics and firebase analytics and stacking both the SDKs on our website page load. We are facing the following issue here - There is a huge difference (approx 30%) in the total session count between GA and firebase.We are getting more session count in GA

FIY - We are referring to the GA dashboard for getting GA session numbers and for firebase session count we are querying the numbers from Bigquery.

Would you be able to kindly assist us with understanding the reason why are we getting a gigantic distinction between the session counts?

Sharing the query which we are using for finding our unique sessions from firebase big query

 SELECT
sessions.date AS Date, count(*) as sessions
FROM (
  SELECT
    DATE(DATE_ADD(TIMESTAMP_MICROS(event_timestamp), INTERVAL 330 MINUTE)) date,
    user_pseudo_id,e.value.int_value as session_id,
  FROM
    `TABLE_NAME.events_*`,
    UNNEST(event_params) e
  WHERE
    _TABLE_SUFFIX>= FORMAT_DATE("%Y%m%d", DATE_SUB(CURRENT_DATE(), INTERVAL 2 DAY))
    AND _TABLE_SUFFIX< FORMAT_DATE("%Y%m%d", DATE_SUB(CURRENT_DATE(), INTERVAL 0 DAY))
    AND event_name LIKE 'Commerce%'
    AND e.key = 'ga_session_id'
    AND event_date>='20210701'
  GROUP BY
    1,
    2,3
    ) sessions
group by 1 
order by 1 desc

Sharing session difference data - enter image description here