[5.0 - POS] Payments do not go into accounting when pos_order is invoiced

[invitu]

When we ask for an invoice in a pos order, the payment move lines are not created in accounting and the invoice is in open state

version : server_5.0.16 addons_2911

steps to reproduce 1 :
- make a new pos order
- clic on "Make Payment"
- check "invoice" checkbox

steps to reproduce 2 :
- make a new pos order
- clic on "Make Payment"
- do not check "invoice" checkbox
- click on button Invoice

result :
- the payments do not appear in accounting
- the invoice is in open state

correct behaviour :
- the payments should be created in the correct journal
- the invoice should be paid/reconciled and in "done" state