I recently had some headache with my Corona code. It ran OK on the Corona simulator but not on the device (Huawei P20 Pro). It turned out to be the launching of a showAlert() from within another showAlert().
This works perfectly on the simulator, but not on the device. To make it work, I had to escape from the first showAlert() before launching the new.
Hope this can help other people running into similar problems.
Leif