Steps to reproduce:

1. Upgraded OS, PHP and Zabbix
2. Go to https://servername/zabbix/zabbix.php?action=charts.view or any dashboard with graphs.
3. See broken layout (date/time)

Result:
See screenshot in attach

Expected:
Normal layout

Additional info:
Reproduced in 2 servers.
Cookie and cache cleared, used browser private windows.
Occurred in Firefox and Edge.
Changing theme and locale didn't helped.