The filter criteria on the lookup table of Lookup join has no effect

1. I joined two tables using the lookup join as below query in sql-client, the filter criteria of (p.name = '??????') didn't shows up in the execution detail and it returned the rows only base on one condiction (cdc.product_id = p.id)

select
cdc.order_id,
cdc.order_date,
cdc.customer_name,
cdc.price,
p.name
FROM orders AS cdc
left JOIN products 
FOR SYSTEM_TIME AS OF cdc.proc_time as p ON p.name = '??????' and cdc.product_id = p.id
; 

2. It showed the werid results when i changed the query as below, cause there were no data in the table(products) that the value of column 'name' is '??????'  and and execution detail didn't show us the where criteria.

select
cdc.order_id,
cdc.order_date,
cdc.customer_name,
cdc.price,
p.name
FROM orders AS cdc
left JOIN products 
FOR SYSTEM_TIME AS OF cdc.proc_time as p ON cdc.product_id = p.id
where p.name = '??????'
;