3.43 is a massive update, congratulations!

It seems that the User-Agent header is not added to tracker HTTP requests, whether set to default, or to a custom one in default client profile. Some trackers use Cloudflare, and the lack of User-Agent absolutely triggers that WWW policeman into blocking the request. The fix is to set it manually in advanced tracker options:
example.com
header:%0D%0AUser-Agent: Tixati/3.43