Just upgraded all Zabbix components to 7.0.3 and confirm the problem with report generation is still there. See attached.

Downgraded zabbix-web-service to the latest 6.4.18 from the previous generation and it doesn't work either. So it seems the last functional version is 6.4.9

Google Chrome 128.0.6613.113

zabbix-agent                           1:7.0.3-1+ubuntu22.04
zabbix-frontend-php                    1:7.0.3-1+ubuntu22.04
zabbix-get                             1:7.0.3-1+ubuntu22.04
zabbix-nginx-conf                      1:7.0.3-1+ubuntu22.04
zabbix-sender                          1:7.0.3-1+ubuntu22.04
zabbix-server-mysql                    1:7.0.3-1+ubuntu22.04
zabbix-sql-scripts                     1:7.0.3-1+ubuntu22.04
zabbix-web-service                     1:6.4.9-1+ubuntu22.04

zabbix-web-service looks ok

2024/09/01 08:38:33.940227 received report request from 127.0.0.1:34194
2024/09/01 08:38:33.940521 making chrome headless request with parameters url: http://172.26.24.31//zabbix.php?action=dashboard.print&dashboardid=343&from=2024-08-31%2000%3A00%3A00&to=2024-09-01%2000%3A00%3A00, width: 1920, height: 1080 for report request from 127.0.0.1:34194
2024/09/01 08:38:35.131636 writing response for report request from 127.0.0.1:34194

PDF generated and mailed successfully

but system log shows multiple errors

Sep 01 08:38:34 moil-zbsrv-01 zabbix_web_service[38239]: 2024/09/01 08:38:34 ERROR: could not unmarshal event: parse error: expected string near offset 800 of 'cookiePart...'
Sep 01 08:38:34 moil-zbsrv-01 zabbix_web_service[38239]: 2024/09/01 08:38:34 ERROR: could not unmarshal event: parse error: expected string near offset 656 of 'cookiePart...'
Sep 01 08:38:34 moil-zbsrv-01 zabbix_web_service[38239]: 2024/09/01 08:38:34 ERROR: could not unmarshal event: parse error: expected string near offset 1208 of 'cookiePart...'
Sep 01 08:38:34 moil-zbsrv-01 zabbix_web_service[38239]: 2024/09/01 08:38:34 ERROR: could not unmarshal event: parse error: expected string near offset 1266 of 'cookiePart...'
Sep 01 08:38:34 moil-zbsrv-01 zabbix_web_service[38239]: 2024/09/01 08:38:34 ERROR: could not unmarshal event: parse error: expected string near offset 1214 of 'cookiePart...'