Have you found solution? I'm unable to flash newest sailfish with flash-on windows bat. commandline disappears after few seconds. I also tried previous sailfish release with same result. I also used newflasher to revert everything normal and try again. I also wonder is it recuired to flash both separate downloads from xperifirm as it suggest two separate downloads "52.1.A.3.137" "190510.001-10073" both few gigabytes large. As I see someone has confirmed it should work (github). Could it related to that I tried aosp11 port & twrp-recovey from xda-developers and messing those files somehow. Can't use linux to test flash for now. Is it correct to keep standalone android platform-tools actual files same place where lies sailfish flashing files? I could not get fastboot work any other ways.