Steps to reproduce:

1. Open Discovery rule edit form
2. Enter invalid custom interval
3. Switch type to Zabbix trapper or SNMP trap
4. Try to Add or Update

Actual Result:

Record is not saved. You'll see an error message about an invalid interval for the entire form. Although these fields already don't exist in your form.

Expected result:
Record can be saved

The task was mvoed from ZBX-27921