Generic prevacid vs brand name

Hi. I'm new to this page so please excuse me if this topic has been beat to death. I've been on Prevacid for quite a while and my symptoms have been well controlled. about a week ago I switched to the Walgreens generic version to cut costs. I've noticed that my symptoms have been returning. Heartburn. Belching. Feeling of a lump in my throat. Is it common or at least possible that the switch from brand name to generic could be causing this? My symptoms seem to return in the late afternoon to early evening. So I'm thinking that maybe the generic aren't timed released and the brand name are. I'm a big poster on the anxiety page so you can imagine that my health anxiety has kicked in big time over this as I've envisioned that I have cancer or some other horrible disease. Any assistance is appreciated.