https://docs.paloaltonetworks.com/pan-os/9-1/pan-os-admin/threat-prevention/prevent-credential-phishing/set-up-credential-phishing-prevention

The best way to view a complete overview of the logs is to select the unified log entry in the side menu. The unified log is a single view that displays all the logs generated by the firewall, such as traffic, threat, URL filtering, data filtering, and WildFire logs1. The unified log allows the administrator to filter, sort, and export the logs based on various criteria, such as time range, severity, source, destination, application, or action1.
Modifying the number of columns visible on the page or the number of logs visible on each page does not provide a complete overview of the logs, but only changes the display settings of the current log view. Selecting the system logs entry in the side menu does not show all the logs generated by the firewall, but only shows the logs related to system events, such as configuration changes, system alerts, or HA status2.
References:
1: View Logs - Palo Alto Networks 2: View and Manage Logs - Palo Alto Networks

Explanation/Reference: https://knowledgebase.paloaltonetworks.com/KCSArticleDetail?id=kA10g000000ClN7CAK