LMS 8.1 Radio & Boom have problems playing transcoded hires files (176.4khz & 192khz)

LMS 8.1 Radio & Boom have problems playing transcoded hires files (176.4khz & 192khz)

Radio stuttered & Boom sounded like 45RPM playing at 33.33RPM (ie. slow)

Logitech Media Server Version: 8.1.0 - 1608700893 @ Wed Dec 23 12:13:04 CET 2020
fell back to Logitech Media Server Version: 8.0.0 - 1605892076 @ Fri Nov 20 21:29:02 CET 2020

LMS running on DEBIAN, Beaglebone Black, file access via NFS from QNAP TS-251D

LMS 8.1 serving FLAC of 24bit 176.4khz & 192khz files
Bitrate: 5960kbps VBR (Converted to 705kbps FLAC)
Sample Rate: 192.0 kHz
Sample Size: 24Bits

LMS 8.1 serving FLAC of 24bit 96khz played okay
Bitrate: 2729kbps VBR (Converted to 705kbps FLAC)
Sample Rate: 96.0 kHz
Sample Size: 24Bits

Above are the same as I'm seeing with 8.0


things tried with 8.1.before falling back to 8.0
- installed LAME to see if Bitrate Limiting could be used as workaround
320bps mp3 worked fine but wasn't needed previously
- updated SOX and flac;
then copied SOX & flac to the LMS hard float directory to check for a possible dependency

Any ideas?

Shall I camp out on 8.0 until the transcode conversations subside?