New BW-16D1HT UHD Oddness

[AlbertB]

Bought a new Asus BW-16D1HT.
Flashed it using the mk-firmware-pack-20191206, using the ASUS-BW-16D1HT-3.10-WM01601-211901041014 firmware.
MakeMKV shows LibreDrive functionality, etc. is enabled as expected.

Blu-Ray's convert fine and process at nearly 6X speed.

I've tried multiple UHD's and most of the time they start at 2X speed and gradually became slower and slower until they are dropping as low as 0.1X speed. This speed would fluctuate somehow, but essentially decrease over an hour to a crawl. It would start saying it would need 1:24 minutes to process. After 20 minutes there would be 2:30 remaining. By 35 minutes there would be 3:25 remaining. By 40 minutes there would be 5:10 remaining. And so on. I've stopped each encode without waiting for it to finish as I assume this is abnormal behavior?

Yet so far I tried John Wick, Blade Runner - The Final Cut, and Spider-Man Into The Spider-Verse and all showed the above behavior. I tried cleaning the discs, but that didn't help.

One UHD disk did work and was done in under an hour: Blade Runner 2049

I tried using three different machines, twice in a Vantec NST-536S2-BK enclosure on two different machines, and once directly in a third desktop machine, so I think I've ruled out cables, enclosure, and computer.

Any knowledgeable thoughts or suggestions?

[Billycar11]

Classic behavior of trash drive I just had a few asus's like that return/ exchange it

[AlbertB]

Solved the issue by using a DVD lens cleaner. Now processing fine with 6X speeds. Surprising, as it's a brand new drive. Guess manufacturers have given up on basic clean room practices.

[AlbertB]

Correction. It worked for two discs, but it's back to acting flaky and steadily slowing down. Guess it's time for an RMA...

[AlbertB]

New drive arrived. Everything is working great now, so it was definitely a bad drive.

[jonghotti]

I’ll add that I took a return from a customer
whose new ASUS was doing this like clockwork.
I went through six complete rips and was unable to reproduce. Started with BD66 then BD100 repeat cycle two more times. While I don’t doubt this occurs it seems intermittent.

[SykesiT]

Did you restore the firmware or leave as is?

Thanks

[jonghotti]

Did you restore the firmware or leave as is?

Thanks

I was ready to but wasn't able to duplicate the issue so no, didn't reload. Still bothers me how it happened immediately to the customer then I get it back and it's gone. Very strange.