Dragging iso file to window doesn't work

[8765pu]

I drag an ubuntu 20.10 iso into the source file section, I get a cursor showing that the action will "+" the file to the list, I let go, and nothing happens.

I have to click "Other" and unintuitively drag the file into that window before I can actually add it.

Ubuntu 20.10
x11

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: usb-creator-gtk 0.3.8
ProcVersionSignature: Ubuntu 5.8.0-45.51-generic 5.8.18
Uname: Linux 5.8.0-45-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.11-0ubuntu50.5
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Mon Mar 22 15:26:12 2021
InstallationDate: Installed on 2020-10-30 (143 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=sv_SE.UTF-8
 SHELL=/bin/bash
SourcePackage: usb-creator
UpgradeStatus: No upgrade log present (probably fresh install)