I have a Juki TI-2010Q, and I'm not crazy about the walking foot. I also feel that the walking foot on my old Singer did a much better job.
I belong to a few Juki FB groups, and the subject of the TL series walking foot comes up frequently. I'm pretty sure that there are some "lemons" out there. Some quilters have succeeded in getting their walking foot replaced.
I don't know if you bought your machine locally and whether you can approach your dealer with this problem.
Keep us posted.