`entry` variable pre-populated on a frontend form
This example code makes use of the entry variable set by Craft to retrieve previously posted data. The variable is set if you encounter validation errors or if you want to modify upon an already saved entry (→ include the entryId in a hidden input field).

The problem is, that you already have an entry variable available to your template because every entry page comes pre-populated with one (if the URI is matched).

Easiest fix would probably be to make this single entry not match the URI set in the section's CP settings. Another idea would be to only fix that title problem and modify the example code:

{% if entry is defined %} value="{{ entry.title }}"{% endif %}


and use this instead:

{% if entry.errors is defined %} value="{{ entry.title }}"{% endif %}