Comment 51 for bug 1818881

from #31, the wifi should work well on preload image 18.04+oem kernel 4.15(also refer to [1]), so it could be a regression on non-LTS Ubuntu. In this case, the crash could be caused by a kernel regression or some binary in linux-firmware.

On non-LTS Ubuntu, there are some ways can be tried.

OEM kernel:
 - refer to this post [2], the machine is certified by OEM kernel, so OEM kernel is supposed to works well on device function.
 - https://bugs.launchpad.net/ubuntu/+source/linux-oem-osp1
 - https://bugs.launchpad.net/ubuntu/+source/linux-oem

mainline kernel:
 - the latest mainline kernel should already include most of the existed fix.
 - https://kernel.ubuntu.com/~kernel-ppa/mainline/
 - a script to help you install it: https://github.com/fourdollars/scripts/blob/master/mainline-kernels.sh

latest linux-firmware:
 - the one you are using looks already the latest one [3]

most of device function failure is supposed to be fixed by the mainline kernel or OEM kernel, then it might take some time to land it to the generic kernel.

BTW, I once test a 9380 by the way of [2], wifi worked well on the combination kernel linux-image-4.15.0-1045-oem + linux-firmware 1.173.9 (more detail about my system information [4]).

Compare the dmesg to yours, the firmware of wifi module looks difference, it could be a clue.
Mine : ath10k_pci 0000:02:00.0: firmware ver WLAN.RM.4.4.1-00079-QCARMSWPZ-1 api 6 features wowlan,ignore-otp crc32 fd869beb
Yours : ath10k_pci 0000:02:00.0: firmware ver RM.4.4.1.c2-00057-QCARMSWP-1 api 6 features wowlan,ignore-otp,no-4addr-pad,raw-mode crc32 e061250a

[1] https://certification.ubuntu.com/hardware/201810-26512/
[2] https://alex-tu-cc.github.io/2019/07/buy-a-certified-ubuntu-machine/
[3] https://qa.debian.org/madison.php?package=linux-firmware&table=ubuntu&a=&c=&s=#
[4] https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1837683