[FFmpeg-user] trimmed audio has wrong duration

[Felix Muster]

I cut the first ten seconds as a sample: _ffmpeg.exe -i _audio.flac -t 10 -codec copy _audio_2.flac
https://gofile.io/?c=pnLfN2

ffprobe still tells me a length of 1:31:29.848938

_ffmpeg -i _audio_2.flac -f null
ffmpeg version N-95216-ge6625ca41f Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 9.2.1 (GCC) 20190918
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 35.100 / 56. 35.100
  libavcodec     58. 59.101 / 58. 59.101
  libavformat    58. 33.100 / 58. 33.100
  libavdevice    58.  9.100 / 58.  9.100
  libavfilter     7. 61.100 /  7. 61.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, flac, from '_audio_2.flac':
  Metadata:
    TITLE           : MILLENIUM_D1_VERBLENDUNG.Title0
    encoder         : Lavf58.33.100
  Duration: 01:31:29.85, start: 0.000000, bitrate: 1 kb/s
    Stream #0:0: Audio: flac, 48000 Hz, 5.1(side), s16
Stream mapping:
  Stream #0:0 -> #0:0 (flac (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, null, to 'pipe:':
  Metadata:
    TITLE           : MILLENIUM_D1_VERBLENDUNG.Title0
    encoder         : Lavf58.33.100
    Stream #0:0: Audio: pcm_s16le, 48000 Hz, 5.1(side), s16, 4608 kb/s
    Metadata:
      encoder         : Lavc58.59.101 pcm_s16le
size=N/A time=00:00:10.08 bitrate=N/A speed= 530x    
video:0kB audio:5670kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

This gives me the correct length: 00:00:10.08

I think there is wrong metadata stored in the file?