Approvals is being set to No Longer Required for a record
The 'mark closed' business rule is marking the record to inactive (active=false)
It is calling 'runMarkClosed' from the 'TaskStateUtil' script include.
The script include is checking below inactive states
SYSTEM_INACTIVE_STATES : [3, 4, 7], // task default inactive/close states
When the record is inactive, the approvals are set to 'No Longer Required'
Set the state to other values not in SYSTEM_INACTIVE_STATES.