How do I solve multiple joins producing duplicate application_id in sql query result

Question

I have this query below and when I include the last join, I keep getting duplicate applicationid is the query result

select distinct 
    a.id,
    a.application_id,
    a.ref_num_sequence,
    a.payment_date, 
    a.payment_status,
    po.name,
    pi.booklet_fee as application_amount,
ph.fee_amount as application_tr_charge,
pi.address_verification_fee,
pi.address_verification_service_charge,
ph.payment_gateway
from applicant a
join processing_info pi on pi.applicant_id = a.id
join payment_header ph  on ph.applicant_id = pi.applicant_id
join passport_office po on po.id = pi.processing_office
where a.payment_status = '200' and 
a.payment_date between '2022-03-04 00:00:00' and '2022-03-08 23:59:59' and 
po.name IN('Enugu','Awka','Owerri','Abakaliki','Umuahia')
order by a.payment_date desc