RealMedia to WAV to FLAC smaller than RM to FLAC

I have an old RealMedia audio file, which I converted to WAV a long time ago. Presumably, the conversion to WAV was lossless. The original rm file:

Audio
ID : 0
Format : ACELP
Codec ID : sipr
Codec ID/Info : Real Player 4
Duration : 36 s 480 ms
Bit rate : 16.0 kb/s
Channel(s) : 1 channel
Sampling rate : 16.0 kHz
Bit depth : 16 bits
Stream size : 71.2 KiB (95%)

The wav file that was created from the rm file:

Audio
Format : PCM
Format settings : Little / Signed
Codec ID : 1
Duration : 31 s 999 ms
Bit rate mode : Constant
Bit rate : 1 411.2 kb/s
Channel(s) : 2 channels
Sampling rate : 44.1 kHz
Bit depth : 16 bits
Stream size : 5.38 MiB (100%)

Using Sound Converter to convert the rm file to FLAC results in:

Audio
Format : FLAC
Format/Info : Free Lossless Audio Codec
Duration : 36 s 480 ms
Bit rate mode : Variable
Bit rate : 264 kb/s
Channel(s) : 1 channel
Channel positions : Front: C
Sampling rate : 16.0 kHz
Bit depth : 24 bits
Stream size : 1.15 MiB (100%)
Writing library : libFLAC 1.3.2 (UTC 2017-01-01)

Why does the bit depth increase to 24?

Using Sound Converter to convert the wav file to FLAC results in a smaller file despite the higher sampling rate:

Audio
Format : FLAC
Format/Info : Free Lossless Audio Codec
Duration : 31 s 999 ms
Bit rate mode : Variable
Bit rate : 217 kb/s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 44.1 kHz
Bit depth : 16 bits
Stream size : 849 KiB (99%)
Writing library : libFLAC 1.3.2 (UTC 2017-01-01)

Am I losing any data by converting from the wav file instead of the original rm file? They all sound the same. Naturally I prefer the smaller FLAC file.