Hey man I just had the same issue. I solved by
executing
1) sudo service NetworkManager restart
2) Ifconfig wlan0 up
Otherwise
1) sudo mordprobe -r ath10k_pci
2) sudo mordprobe -r ath10k_core
3) sudo mordprobe -r ath10k_core rawmode=0 cryptomode=0
4) sudo mordprobe ath10k_pci
Hope it helps.