Hi ! thanks for replying. Can you guide me through this step by step on how exaactly to do it as i have less knowledge about databases and queries. Thank you so much

Ok. First make sure you are doing it on a test database.

1. Run a sql delete query on hr_leaves table. (delete from hr_leave)

2. Now delete from mail activity table. (select * from mail_activity)

But make sure you are doing it in some test database and have no other activities in mail_activity table.

After doing above two steps, create new leaves and you should not face that problem.

There is another point. Check your Technical > Resource > Working Times

Weekends and Global Leaves do not include in Leaves counts.