@Thammada can you provide example code?

I can confirm it,
@zero-24 as example you can use xml from that pull #3574

I have no idea how it can be fixed, without another dirty hack

Hi,
I'm a student, interested in joomla and i would like to contribute (first time).
I don't really understand how to re-create the bug. Can someone help me please ?

@zero-24 the following xml snippet can be used as an example

<field name="test" type="repeatable" icon="list"
        label="Test" description="Test descr"
        default=""
        maximum="5">
    <fieldset hidden="true" repeat="true">
        <field name="test_media_preview" type="media" directory=""
            label="media" description="test_media_preview" preview="true"/>
        <field name="test_media_tooltip" type="media" directory=""
            label="media" description="test_media_tooltip" preview="tooltip"/>
    </fieldset>
</field>

The issue is caused by the function incresseAttrName (should be increaseAtrrName by the way) in /media/system/js/repeatable.js which renames all input fields to avoid duplicate input ids by appending an integer suffix. However the code which is used to update the preview of the type="media" also use suffixes like _preview_empty and _preview_img.

For example id="field_name" becomes id="field_name-1" and id="field_name_preview_img" becomes id="field_name_preview_img-1" but the preview function looks for id="field_name_preview-1_preview_img"

I suggest fixing in repeatable.js by using a prefix instead of suffix to prevent duplicate ids, would there be another conflict in that case?

Edit: It would be better to find ids ending with _preview, _preview_img and preview_empty, this does solve the issue when the attribute preview="true" is set, but does not solve the problem when preview="tooltip"

@Fedik do you know what causes the tooltip not to show up?

I'm going to close this issue in favour of #6882 which is the same issue but has a more detailed conversation in - to keep things in one place :)