Steps to reproduce:

• Open discovery create/update form
• Add e.g. FTP check or any another except Zabbix Agent
• Open FTP Discovery check edit popup
• Change type to Zabbix Agent
• Add agent key and Click update
• Verify console and 'Checks' section

Result: PHP TypeError appears:

Uncaught TypeError: Cannot read properties of null (reading 'closest')
    at Object._addRadioButtonRows (<anonymous>:225:86)
    at Object._addCheck (<anonymous>:191:9)
    at Object._updateCheck (<anonymous>:64:8)
    at HTMLDivElement.<anonymous> (<anonymous>:99:10)
    at <anonymous>:148:19

Please see video attachment:

Expected: discovery check should be edited correctly without errors.