Mine is an LG BP50NB40 from Best Buy.
Using Windows 10, plugged both cables directly into the motherboard (AM5)
Using sdftool flasher 1.3.6
1) First flashed "HL-DT-ST-BD-RE_BP50NB40-NB50-1.03-NM00800-212005070917.bin"
2) Select Recover, select "DE_LG_BP50NB40-NB50_1.03_MK.bin", then select "DE_LG_BU40N_1.00.bin", hit START
3) unplugged & replugged drive in, instead of making sounds for awhile, then quitting, a 4k disc showed up & I started ripping.
I really hope this helps, since I was about to call it a day & return the drive.
Further notes upon testing, ditched the Micro USB to dual USB A 2.0 cable & used a Micro USB to USB C connector, used an Anker USB C cable I normally use for charging, also tried an Anker USB C to USB A cable (Specs: 15W (3A/5V)), connected it to USB 2.0/3.0/4.0, everything I listed worked just fine for 4k UHD/Blu-ray ripping.