The behavior you’re describing is indeed a default behavior in Odoo for 'one2many' fields. However, there isn’t a straightforward configuration option to disable this auto-selection feature.

To change this behavior, you would likely need to modify the Odoo JavaScript code that handles this auto-selection. This would involve extending the relevant widget in the Odoo JavaScript framework to override the default behavior.

Here’s a basic example of how you might do this:

odoo.define('your_module.field', function (require) {

    "use strict";

    var fieldRegistry = require('web.field_registry');

    var FieldText = require('web.basic_fields').FieldText;

    var FieldTextNoAutoselect = FieldText.extend({

        events: _.extend({}, FieldText.prototype.events, {

            'click': function (event) {

                event.stopPropagation();

            },

        }),

    });

    fieldRegistry.add('text_no_autoselect', FieldTextNoAutoselect);

    return FieldTextNoAutoselect;

});

In this example, a new field type 'text_no_autoselect' is created by extending the 'FieldText' widget. The click event is overridden to stop the propagation of the event, which should prevent the auto-selection.

Hope this helps.

Best regards,
Maciej Burzymowski