Increment by 1 in sequence numbering and dynamically partitioned tables

Question

I am using dynamically created table partitions to store event information in a Postgresql 13 database. The master table from which the child tables inhert their structure contains an id field with an auto-incrementing sequence. The sequence, master table and trigger for inserts look as follows:

CREATE SEQUENCE event_id_seq
INCREMENT 1
START 1
MINVALUE 1
MAXVALUE 9223372036854775807
CACHE 1;


CREATE TABLE event_master
(
    id bigint NOT NULL DEFAULT nextval('event_id_seq'::regclass),
    event jsonb,
    insert_time as timestamp
)

CREATE TRIGGER insert_event_trigger
BEFORE INSERT
ON event_master
FOR EACH ROW
EXECUTE PROCEDURE event_insert_function();

Additionally, the event_insert_function() uses the following code to insert new rows posted to the master table:

EXECUTE format('INSERT INTO %I (event, insert_time) VALUES($1,$2)', partition_name) using NEW.event, NEW.insert_time);

When looking at the sequence numbers in the id field, I only get every other number, i.e. 1,3,5,7, ...

Based on some related information I found, I assume this has something to do with Postgresql counting the initial insert into the master table and the triggered insert into the child table as two occurences. So my first question is, whether this is correct, and if so what's the rational behind it and why not "pass through" the insert from master to child?

More importantly though, what do I need to do to set up a properly incrementing sequence (i.e. returning 1,2,3,4 ...)?