Progress bar stuck on 0% when installing Flatpaks

One day I tried to install some app from flathub repo. That app also needed a big runtime, which I didn't have. I've pressed install button, progressbar appeared, something like "Installing 0%". 5-10 minutes later it was still 0%. I cancelled the installation and continued with commandline. For some reason, I had very slow connection to flathub, something like 200kB/s, so it took much time to install it, but I saw progress and what happens (downloading/installation). In case it matters, it was on Fedora 29.

Gnome-software should provide detailed information about flatpak installation progress.