Why does a Bash script using ack return different counts when executed from cron versus an interactive shell on AlmaLinux 9?

When running a Bash script that uses ack to search for patterns in a file, the script reports the expected counts when executed directly from an interactive shell on AlmaLinux 9. However, the same script invoked via a cron job returns zero counts, causing the conditional logic to fail. What causes this difference in behavior, and how can the script be modified to produce consistent results regardless of execution context?