Database trigger taking a long time

my project requires importing order and delivery data as CSV files. Once the delivery data is imported, I am using a database trigger to update the order records with address details from the delivery records.
the trigger that i am currently using looks at an “updated” field in the delivery table (Delivery History Before Change’s Updated is empty) to see if it is empty and if it is, it then updates the order table record with a matching order number and adds the various address field data.
trigger

Once that is complete, it then then supposed to update the “Updated” field in the delivery table to “yes”.

I am having 2 problems:
the trigger seems to work to the extent that the order table is updated but it can take up to several hours to execute.
the second operation which should update the delivery table record is not working.
the data set involved is relatively small (20 - 99 records) and is limited at the upper end by the CSV constraint.
i am currently on a personal plan. I have tried boosting processing units but it does not seem to have any impact. Will upgrading to the professional plan resolve the delays? if that will solve the problem but i hesitate to do that if it won’t resolve the delay issue.
Also can anyone tell me why the second part of the workflow does not seem to work?

Hi,
i’m trying to bulk import like 100 rows but only 20 triggers are fired.
Do you know how to fix that?