Absence type is maintained for Full day and need to get delimit for attendance of half day

Hello,

I have requirement where Absence type is maintained for Full day and need to get delimit for attendance of half day

I have changed settings to A for system reaction for time constraint 3 for both absences and attendances but still if Full day absence is maintained and try to create half day attendance, it doesn't delimit and shows collision error. However, with same settings if full day absence is maintained and full day attendance is entered on same day it deletes the record of absence.

Please let me know what need to be changed in order to maintain half day attendance over full day absence?