Thank you to all who shared their files. We do not support flag, fish effects on a straight line with just two anchor points. The feature is implemented to work on the line segment which is not straight.
Please refer to the attachment for supported and non supported scenarios. Should you have further query please email us on sharewithai@adobe.com

Hi All,

I am closing the ticket due to lack of response.

Please get in touch with us at sharewithai@adobe.com or any of the other support channels – https://helpx.adobe.com/support.html . Please give a reference to this post so that we can identify you.
Till now we have received only one case where the WARP Effect is not working & that is of “Straight Line”.

Please note that Warp Effect for Straight Lines is not supported. If needed this can be tracked as feature request.

Please let us know if there is any another scenario where this effect is not working.

With Best Regards,
Illustrator Team

Reminder 2:

Hi All,

Thanks for sharing the video, it helped us to understand the issue better.
Till now we have received only one case where the WARP Effect is not working & that is of “Straight Line”.

Please note that Warp Effect for Straight Lines is not supported. If needed this can be tracked as feature request.

Please let us know if there is any another scenario where this effect is not working.

With Best Regards,
Illustrator Team

Reminder:
We apologize for having such an irritating issue with your workflow.
The issue is still not reproducible in-house. We need your help to reproduce the issue.
Please provide your system details and the objects with which you are working.
If issue is happening in any specific file and you can provide the file to us at ShareWithAI@adobe.com, also please do mention this User Voice thread link in the mail.

Hi,

We apologize for having such an irritating issue with your workflow.
The issue is still not reproducible in-house. We need your help to reproduce the issue.
Please provide your system details and the objects with which you are working.
If issue is happening in any specific file and you can provide the file to us at ShareWithAI@adobe.com, also please do mention this User Voice thread link in the mail.

Thanks & Regards,
Raghuveer Singh