OS: Android Oreo; device: Huawei Mate 8; application called by Firefox to select files to upload: file manager (from Huawei). Problem: when push the button to select files to upload, Firefox force selection of one of the following phone application (file manager, galery, camera) to select files. Selecting the file manager, the application offer posibility to select files. After several files were selected, when finishing selection and submit form, only the first file is submited. Opera for Android, using the same file manager, do not make this error but submit all selected files. Is not a question, is a request for correction.