This issue happen to some people (including me) as you can see from the forum post.
I had to manually change the audio output device from gnome setting everytime I unplug my headphone. It was suppose to automatically change the audio output to my laptop speaker.
I think this happen either last update or the one before that.
My sytem information:
- OS : Solus 4.1 5.10.9-169.current (Gnome)
- System : Lenovo ideapad Y700-15ISK
- CPU : Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
- Graphics : NVIDIA GeForce GTX 960M / Intel HD Graphics 530
- Audio : Intel 100 Series/C230 Series Chipset Family HD Audio Controller