Please do a test.
Boot with the regular kernel (5.0.0-35-generic), make sure the speakers can work after booting, then run:
amixer sset 'Auto-Mute Mode' 'Disabled'
After that plug a headphone and unplug the headphone, does the speaker still work?
Please do a test.
Boot with the regular kernel (5.0.0-35-generic), make sure the speakers can work after booting, then run:
amixer sset 'Auto-Mute Mode' 'Disabled'
After that plug a headphone and unplug the headphone, does the speaker still work?