Interestingly, this policy isn’t visible on the UK version of the QR website. I managed to find it via Google which took me to the South Africa version of the site, and the policy was there. Website glitch, or market specific policy?

I’ve got a F ticket on BA LHR - DOH and a separate J ticket DOH - BKK on QR. Both airlines have told me I cannot interline and will need to collect my bags at DOH. 8 hour connection.