When an iOS 14 beta device is connected to my MacBook running Big Sur 11 beta 10, files can be transferred to the iOS device via Finder, but not from iOS to the MacBook. No error is given and the transfer drag-and-drop appears to have worked as normal, except the file doesn't get transferred. It worked in the previous beta of Big Sur, although was problematic in earlier betas.
macOS Big Sur 11 beta 10 file transfer from iOS 14 beta
Fixed as at Mac OS 11.0.1 Beta (20B5012d)
Problem seams not solved since document and image transfer to MAC hangs up after confirming image on iPhone with Big Sur 11.1.