Can no longer export from Mac to iPhone

[bennet...@gmail.com]

The export from iFlash to iFlash Touch has abruptly stopped working for me after many months of successful use. I've tried the usual rebooting the app, the phone, the computer, etc. I've also tried clearing the device list in the Export drop-down menu, and now iFlash can't find my phone at all on the network. All to no avail. The only difference I can think of between now and the last time I exported is that I upgraded to MacOS Big Sur. Anyone else have this problem? If so, what to do?