Set the QT_BEARER_POLL_TIMEOUT environment variable to -1
I work on a Qt powered project and we had the same bug
Tried that, it did nothing. The only thing that worked for me was to delete the library entirely. At which point I'd ask why they bother including it in the first place if it's unnecessary and causes issues.
On windows there's some bug with a qt library they're using that, of all things, messes up network connectivity. It does polling of the network interfaces every 30 seconds (I believe) which causes traffic to completely stop for a couple of seconds.
On Android at least, it is EXTREMELY slow. Search works about 10% of the time, and the other 90% of the time you have to kill the app and relaunch it.