I’m writing all of this assuming that DNS is the problem, like it was for the other “smart” devices. Side note: even if I try hard, I can’t consider it a “mistake” of knot-resolver, as even though the behavior is different from most other implementations on this, all is perfectly within standards.
The least-impact workaround is in this post: Yamaha receiver problem with Knot DNS It changes the DNS provider for that particular device to Google’s public servers; you may want to put your ISP’s servers instead, for example. I believe editing files is easy enough through putty (or maybe winscp).
Future Turris will contain versions that will no longer exhibit this difference, but I can’t personally promise when that will happen: Garmin products unable to use Wifi despite IP address attributed