When clicking through the host graphs /graphs.php?context=host&page=4 it goes to a blank page. Looking at the php logs we get:

[Sat Jun 08 11:14:13.711280 2024] [php:warn] [pid 1305477] [client 103.51.114.32:53578] PHP Warning:  Undefined array key 9346 in /usr/share/zabbix/graphs.php on line 722, referer: http://removed.com.au/zabbix/graphs.php?context=host&page=3

[Sat Jun 08 11:14:13.711381 2024] [php:warn] [pid 1305477] [client 103.51.114.32:53578] PHP Warning:  Trying to access array offset on value of type null in /usr/share/zabbix/graphs.php on line 722, referer: http://removed.com.au/zabbix/graphs.php?context=host&page=3

[Sat Jun 08 11:14:13.711422 2024] [php:error] [pid 1305477] [client 103.51.114.32:53578] PHP Fatal error:  Uncaught TypeError: array_key_exists(): Argument #2 ($array) must be of type array, null given in /usr/share/zabbix/graphs.php:722\nStack trace:\n#0 {main}\n  thrown in /usr/share/zabbix/graphs.php on line 722, referer: http://removed.com.au/zabbix/graphs.php?context=host&page=3

I believe this is due to graphs referring to objects which have been removed as this zabbix instance has been upgraded multiple times.