Steps to reproduce:

• Start the server and collect some data for Zabbix server host
• Create graph widget with =>
  -) Data set host patterns => Zabbix server; item patterns => Available memory; Draw => Points e.g.
  
  -) Axes Max => 0 e.g.
  
• Save widget and dashboard
• move mouse pointer over the graph or try to zoom time area on the graph

Result: Js error "Uncaught TypeError: Cannot read properties of null (reading 'tagName')" appears.



Expected: No errors should appear.