Runnig it now against latest master, including all the pull requests you've send to NBD.
The router seems to run faultless with the previous ATH firmware and your pull requests, but with this one dmesg is flooded with:
[21952.327921] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
[21952.416374] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
[21954.873996] ath10k_warn: 5 callbacks suppressed
[21954.874012] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
[21955.084142] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
[21955.183536] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
[21958.360060] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
[21959.690105] ath10k_pci 0001:01:00.0: Invalid VHT mcs 15 peer stats
There is a discussion about the same error here: https://www.spinics.net/lists/linux-wireless/msg167522.html
but i can't really make head or tails from it yet. Seems we backport this 4.14 ath10k driver to 4.9?
anyway. ideas to fix this error are appreciated.