MIDI music not playing on Linux

[shortnameswill]

I've tried the only guide I could find, doesn't work, I'm using the Flathub version of SRB2 2.2.11 but it has been a problem since 2.2.9 for me.

Image 1: Console error when loading MIDI Music (Nothing plays, just eerie silence)

Image 2: No settings to change soundfonts

 

[DylanDude]

Just to be clear, the soundfont options are exclusive to the Windows version.

 

[A_3TO_GAS_MAN*(RUS)*]

Just to be clear, the soundfont options are exclusive to the Windows version.

Why?