Native HTML5 HLS doesn't call child playlist with master playlist URL

Since iOS 13, the issue is present and reproducible each time. I've tested with several devices on iOS 12.x, the issue is not present.

A test URL (we're currently working on a workaround on our side, so it might not have the error when you test it)

https://pub-master.recette.6play.fr/pekin-express-p_945/sur-la-route-avec-stephane-rotenberg-le-controle-technique-c_12441303?player.ad.enabled=false&applaunch.authentication.displayMode.longForm=none

Expected behaviour (as of Safari 12, iOS12, in the screenshots):

• Load a 30x resource (video.src=) https://lbv2.cdn.m6web.fr/v1/resource/s/usp/mb_sd3/7/c/3/Zone-interdite_c12502375_Heritage-le-pactole-/Zone-interdite_c12502375_Heritage-le-pactole-_drmnp.ism/Manifest.m3u8?....many things behind
• Redirects to the correct edge behind the load balancer https://e112.cdn.m6web.fr/usp/mb_sd3/7/c/3/Zone-interdite_c12502375_Heritage-le-pactole-/Zone-interdite_c12502375_Heritage-le-pactole-_drmnp.ism/Manifest.m3u8?st=Rdy_Lee8BBci3slvx8I3vg&e=1569267031
• Loads a child playlist with the real master playlist URI https://e112.cdn.m6web.fr/usp/mb_sd3/7/c/3/Zone-interdite_c12502375_Heritage-le-pactole-/Zone-interdite_c12502375_Heritage-le-pactole-_drmnp.ism/Zone-interdite_c12502375_Heritage-le-pactole-_drmnp-audio1=93468-video_eng=300000.m3u8 (which leads to a 200)

Obtained behaviour (as of Safari 13, iOS13):

• Load a 30x resource, see above
• Redirects to the correct edge behind the load balancer, see above
• Loads a child playlist with the 30x master playlist URI: https://lbv2.cdn.m6web.fr/v1/resource/s/usp/mb_sd3/f/5/3/Bull_c12487211_Saison-3-episode-4/Bull_c12487211_Saison-3-episode-4_drmnp.ism/keyframes/Bull_c12487211_Saison-3-episode-4_drmnp-video_eng=800000.m3u8 (which leads to 400 Bad Request)

FYI: I've submited a feedback through the Feedback assistant