I have exactly the problem.
And the comments on the following links shows that the problem is common for audio chip
and it seems that it is a problem in kernel.
The result of
cat /proc/asound/card0/codec* | grep Codec is
Codec: Realtek ALC295 Codec: Intel Kabylake HDMI
and as you can see that it uses the same sound chip as appeared on the first link. My laptop is also brand new like it appeared on the first link. I suspect that it is a software problem, not a hardware problem.
I tried both of the solutions in the second link (which is from 4 years ago!) but none worked.
relevant output from
lspci -v is
00:1f.3 Audio device: Intel Corporation Device 9d71 (rev 21) Subsystem: Hewlett-Packard Company Device 81a9 Flags: bus master, fast devsel, latency 32, IRQ 292 Memory at b1228000 (64-bit, non-prefetchable) [size=16K] Memory at b1210000 (64-bit, non-prefetchable) [size=64K] Capabilities:  Power Management version 3 Capabilities:  MSI: Enable+ Count=1/1 Maskable- 64bit+ Kernel driver in use: snd_hda_intel Kernel modules: snd_hda_intel, snd_soc_skl
and kernel information
Linux computername 4.10.0-20-generic #22~16.04.1-Ubuntu SMP Thu Apr 20 17:43:29 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
I think this problem is NOT a duplicate of the second link (although it technically is a duplicate of the first link).