itch.io

Had the same issue...go into your device settings and turn off mobile data completely, also turn sleep mode off on the phone screen and try the download.  You need to have at least 8GB (might be 16 for some idiot browsers) of storage on your device not the SD card as the download gets staged there before it is moved to the destination location.  Biggest two things is if your internet fades out and the device tries to switch to a different network the download will timeout and you won't be able to reconnect, you may need to delete the files and cookies related to the broken download in order to reinitiate the file transfer.

At the end make sure you stay on the download page until the entire file appears in your file manager...this is far from an instant process.  The download will get staged in your browser cache on some devices then moved from the cache to the destination location.  Its a pain but totally worth it.