DNxHR LB not playing in Resolve 17.0B build 15

First post here.

AvidCodecsLE.2.7.6 installed from avid.
Windows 10 Pro 64 bit (10.0 build 18363)

Downloaded some tutorial files here:
https://vfxstudy.com/tutorials/set-extension

Restarted the machine.

One file with DNxHD 45 shows up and plays fine, the others, DNxHR LB cannot play on this system. Error message states "codec not supported."

The files all play fine on a 2010 Mac with the avid codecs on the QT player 7.6.6.

Unlikely a Resolve issue, but can someone suggest what's happening? Haven't been on a Windows based workstation in years and I thought they had silly issues like this resolved (to use a bad pun).

I can download these files as MP4 as a workaround, but, what if I couldn't AND I didn't have a mac to test them on?

Insights greatly appreciated!

Uninstall the Avid codecs. It shouldn't be needed and might be interfering.

I second that. I have no codecs installed, just DR 17, and all flavors of DNxHR work as expected.

Forgive my late reply! Curiously, I didn't download the avid codecs UNTIL I could not see the videos.

I'll try some other things and give it a shot! Been busy avoiding Los Angeles COVID! ugh!