playbin3 fails to start playback on network filesystem files

Fedora 33, gstreamer1-1.18.0-1.fc33.x86_64

playbin works fine (GST_DEBUG 4):

└─ gst-play-1.0 sftp://spw/home/webserver/www/bg.jpg
Press 'k' to see a list of keyboard shortcuts.
Now playing sftp://spw/home/webserver/www/bg.jpg
Prerolling...
Buffering... 100%  
Reached end of play list.

playbin3 freezes (GST_DEBUG 4):

└─ gst-play-1.0 --use-playbin3 sftp://spw/home/webserver/www/bg.jpg
Press 'k' to see a list of keyboard shortcuts.
Now playing sftp://spw/home/webserver/www/bg.jpg
Prerolling...

I'm hitting the same from my app using playbin3. It never finishes pre-rolling after setting it to Paused.