HDR stopped working with latest K Lite release

Today I updated K lite to the current version and HDR stopped working altogether. Previously madVR was able to activate HDR automatically. When that didn't work I manually turned it on in Windows. That didn't work either. I confirmed madVR was enabled and set to pass through HDR data. I then tried updating to the current Nvidia drivers and also ran the optimization tool but that didn't fix the issue.
Any ideas?

Edit.
Also I believe I was previously using version 15.6.8

It should still work with current version.

Look at:
MPC-HC menu > View > Filters
LAV Video Decoder should be used as decoder. You must use the internal subtitle renderer. You can not use ffdshow decoder/processor or VSFilter.

If that is all correct, then press Ctrl+J to show the madVR statistics overlay. That should indicate if it recognizes the HDR metadata. It that is also correct, then it must be a driver issue. NVIDIA broke HDR recently, and supposedly fixed it it the latest one.

Thanks. It turns it was my subtitle renderer setting. I had changed it to VOB for some other content since it wasn't handling ASS sub correctly

The internal renderer should normally handle ASS just fine. If you encounter that issue again come here with details about the file, then I can check it.