Chrome opens a second Transmission window with magnet links. How does it check if there is a transmission open or not?

The magnet link is correctly set with xdg-mime to open in transmission, and also in .local/share/applications/mimeapps.list. If transmission is NOT running, everything works as expected (click a magnet link or torrent file, and it opens). If transmission is running, clicking on a magnet link in chrome will open a second transmission window. This does not occur neither in firefox nor with the command xdg-open "magnet-link". The problems seems to be only in chrome. Tech specs: Debian buster with 4.19.0-2-amd64, fully upgraded. transmission-gtk 2.94 (d8e60ee44f) google chrome Version 72.0.3626.81 (Official Build) (64-bit) xdg-open 1.1.3 awesome WM v4.3 edit: Checking chrome's log, I can see this related line [21407:21407:0207/152959.142127:VERBOSE1:navigator_impl.cc(111)] Failed Provisional Load: magnet:?xt=urn:btih:, error_code: -3, error_description: The webpage at might be temporarily down or it may have moved permanently to a new web address., showing_repost_interstitial: 0, frame_id: 4