Problem description: when entering a new entry, successfully saving it and reloading the page, the confirm form resubmission popup is shown and after clicking “continue” a new input form is opened with the just entered values in input fields. An error message is displayed, that an entry with such values (depending in if you’re entering a Discovery rule, Host prototype, Discovery prototype or Web scenario) already exists.

See example:

Steps to reproduce:

1. Go to Data collection -> Hosts -> Zabbix server -> Discovery rules
2. Create a new discovery rule with name ‘test1’ and key ‘trap’
3. Click Add, observe the green message stating ‘Discovery rule created’
4. Reload the page
5. Observe the popup ‘Confirm Form Resubmission. The page that you're looking for used information that you entered. Returning to that page might cause any action that you took to be repeated. Do you want to continue?’
6. Click Continue

Actual result: A new input form is opened with the just entered values - name ‘test1’ and key ‘trap’ - in input fields and an error message is displayed with text ‘Cannot add discovery rule. An LLD rule with key "trap" already exists on the host "Zabbix server".’

Expected result: the Discovery rules list is reloaded, the popup ‘Confirm Form Resubmission' doesn't appear, the message 'Discovery rule created' disappears.

Reproducible on Discovery rules, Host prototypes, Discovery prototypes, Web scenarios.

Updating an existing entry, deleting an entry from a list or from form also produces similar errors in Discovery rules, Host prototypes, Discovery prototypes, Web scenarios with the popup 'Confirm Form Resubmission' involved.