LG vs Lite-On BD drive - different FS for same disc

I have two drives:
LG WH14NS40 (firmware 1.01-A1)
Lite-On iHBS112-2 (firmware PL06)

disc: data DVD+R burned with ImgBurn, with ISO9660 + UDF 1.02
I assume this is the UDF bridge format

OS: Windows 7 Home Premium, latest updates
both drives connected to same mobo chipset controller

when I put the DVD+R in the LG, Windows uses the old ISO9660 format, which makes the disc almost useless with its 8.3 names.

when I put the same disc into the Lite-On, it properly uses the UDF filesystem instead.

But this does not happen with data BD-Rs burned with ISO+UDF. The LG only chooses the UDF filesystem for the BD.

Why might the LG behave this way and how do I tell the LG drive, or tell Windows I want it to prefer UDF if available?

Can the LG read the entire disc ok? Check that by verifying the disc or reading it to an image.

If the OS can’t read the UDF descriptors properly (unreadable disc or the disc size is reported incorrectly so they aren’t where they should be etc.), it’ll fall back to ISO9660 or whatever else is on the disc.

That was the symptom I was previously getting, even after switching between the two drives a couple of times.

I don’t know if it was because I brushed off the surface with my shirt, but after doing a disc quality check of the DVD in the Lite-On, I switched back to the LG, and now it works (reading UDF)!