Sudden Heartburn-Like Symptoms with Adderall XR and Sertealine

I've been on Adderall XR and Sertealine for about four years now with little to no side effects. Now, out of the blue, having not changed anything about medications, diet, or lifestyle I'm getting horrible heartburn-like symptoms whenever I take them. I don't understand why, I take them with food and literally nothing's changed in my routine recently. Has anyone else experienced this or have any idea how to fix it? I already take my meds with food and have tried adjusting the amount of food I eat and the times I take my meds, but it hasn't helped. Alternatively, do you have any advice on counteracting heartburn like pain or avoiding it? Thanks so much, ✧E