Sorry, I do not have a time to figure out a way to detect the firmware version, trace down since which firmware version the behavior has changed, and create a PR. But maybe just dumping this info here already helps others.
This is an unofficial archive of firmware, software, and manuals for the FNIRSI FNB58 USB Tester. Quick FAQ How do I upgrade the firmware? Unzip the software somewhere on your PC. There is no installer, it acts like a portable application that you can place anywhere and just run. ...
FNIRSI-138 PRO Handheld Digital Oscilloscope 2.5MSa/s 200KHz Analog Bandwidth Support AUTO 80Khz PWM And Firmware UpdateUSD 23.14-26.14/piece FNIRSI FNB38 Current And Voltage Meter USB Tester QC4+ PD3.0 2.0 PPS Fast Charging Protocol Capacity TestUSD 16.00/piece ...
FNIRSI-138 PRO Handheld Digital Oscilloscope 2.5MSa/S 200KHz แบนด์วิดท์แบบอะนาล็อกอัตโนมัติ80Khz PWM และ Firmware UpdateUSD 23.14-26.14/piece FNIRSI FNB38 Current และมิเตอร์ว...
FNIRSI FNB48 and FNIRSI C1 are known to work. It will use first that it finds. FNIRSI FNB58 is also known to work, thanks to work of @didim99. FNIRSI FNB48S should also work. Make sure to have relatively recent firmware. My FNIRSI C-1 came with very old firmware (0.20) that did...
An unofficial archive of firmware, software, and manuals for the FNIRSI FNB58 USB Tester - Rhomboid/fnb58-archive