I noticed that the Zabbix panel displays a maximum of 20 recent events, and the rest should be viewed in groups of network nodes.
To increase the number of recent events displayed, open the file ../zabbix/include/defines.inc.php in any editor, for example, in nano:
sudo nano /usr/share/zabbix/include/defines.inc.php
and approximately on line 537 we find the following:
Let’s change the number 20 to 150, for example, and save the changes, then 150 recent events will be displayed in the Zabbix panel.
By the way, in the nano editor, the keyboard shortcut Ctrl+W is used for searching, Ctrl+O and Enter to save, and Ctrl+X to exit.