Play is fine, FF-REW and playback locks up

[jsmiddleton4]

First time poster. DVDFab user who is migrating over to MakeMKV.

Been playing with sources that have LPCM Multichannel. The current MakeMKV beta seems to be doing okay and when I playback the MKV via Acrsoft Theater or via my PIVOS AIOS as long as I don't hit FF/REW playback is quite good.

If I hit the FF or REW command playback locks up. I've tried this on several blurays with same result. Also tried directly from my bluray drive and using MakeMKV for everything as well as using DVDFab to archive the disk to .iso and testing.

MakeMKV reads everything fine. No errors reported in process. MKV file shows both audio tracks with Mediainfo. I am not converting anything to FLAC, no header edits, etc., as MakeMKV Beta appears to be handling the LPCM Multi-channel track correctly. The LPCM Multi-Channel track is available for me to select in my playback software and does indeed playback in multi-channel.

I tried the FLAC option in MakeMKV and have same result as just noted.

I do not know why FF/REW cause the lockup.

Other mkv's that were made with DVDFab V8 FF/REW just fine.