ok @Anonymous got it.
Schedule as before bu this time only add the Monday.
Steps
Interval: 1
Frequency: week
Timezone: your timezone
At these hours: your hour
At these minutes: your minutes
Settings
Trigger Conditions: @less(int(utcNow('dd')),8)
The add a Planner steps
Group ID: yours
Plan Id: yours
Bucket: if you wish to set one
Start Date Time: an expression utcNow()
Due Date Time: an expression addDays(utcNow(),7)
That will do it.
Try it now with the following example

This will create a task as you wish.
hope it helps,
R