If it is this easy to reproduce, maybe we should file a bug report - it is really annoying/buggy behaviour. I am not opening the network folder, so maybe it’s trying to greedely cache media files for preview thumbnails or something, I don’t know…

For what it’s worth, my KDE file browser would freeze up when I had a WebDav network drive to a server that went offline, not exactly elegant either, just opening my home folder and randomly after a second or two …… all software can bug in bad ways.