Hello, I had to go back to the kernel 4.14 to try to resolve a problem, but unfortunately, my wifi (Qualcomm Atheros QCA9377 802.11ac) was not detected by the kernel 4.14, but there was a solution in this thread: Dec 02 Update & QCA9377 Wireless
To resolve the problem he posted a command with a route, but now that route is a little different or maybe is only different for some users, so there is an update for that solution just in case:
Wow, this problem is still a thing today? I remember having that issue in October 2018 (which forced me to upgrade to Linux 4.19).
I wonder if it is Qualcomm not giving a sh- about making their firmware working with older kernels or if it just Linux 4.14 that is just too stubborn for some reasons and absolutely want to use this firmware even if it isn't compatible. (Of course, I have no idea how linux firmwares in general are supposed to work by the way.)
It seems to only be this one adapter of theirs that has this issue with the firmware version. I can't think of any other adapter that has this issue. The QCA9377 adapter has more problems than you could shake a stick at over the last year.
I'd say it's about a dead heat for the worst adapter of the year, tied with the rtl8723be. Wouldn't touch either with a ten foot pole.
I remember that during the first year with this notebook I had to install the firmware manually from github. Then they added the firmware from the kernel 4.4 if I don't remember bad. Then the next 3 years I had no problems with this wireless on different distributions. This was the first time that I had a problem, only on Manjaro with 4.14. But the rest is a good hardware, but not the best of course.
The sad part is that this adapter, and one other Atheros adapter really affect being able to blanket recommend Atheros chips. The QCA9377 & QCA6174 are the only real dogs in their line up. Other than those 2 chips you really can't go wrong buying Atheros.
Intel has a couple of dogs as well, but otherwise they're pretty good. If I had the choice I'd go Atheros though, as Intel has been having a fair bit of firmware issues of their own.