I have a Netgear WNR2200 and a WNDR3800 and on both I had OpenWRT 19.07.03 installed and with both routers I have the problem that when I am connected via WIFI the web pages are loaded delayed or paused long before the web page is loaded.
For comparison I installed the Stock Firmware and DDWRT on both of them. With DDWRT I have worse wifi performance but no pauses or delays when loading web pages. With the stock firmware there are no problems with the wifii performance on both routers.
This problem only occurs with wifi connections in the 2.4 or 5 GHz band. With LAN connection it works without problems.
Could it be that the ATH9K drivers are just bad and if so it makes no sense to install OpenWRT on these routers.
Have the similar problem. It looks like "rekeying issue". Try to disable hw encryption (/etc/modules.d/ath9k, ath9k nohwcrypt=1 and reboot).
Also try to disable GTK & PTK rekeying /etc/config/wireless
config wifi-iface 'default_radio0'
option device 'radio0'
option wpa_group_rekey '0'
option wpa_pair_rekey '0'
It work for me quite well.
Also you may find a lot info from Alexander Wetzel, just for example:
Known devices/systems not able to rekey the PTK correctly:
- any linux system using ath9k with mac80211 from kernel < 4.20
- HTC 10 smartphone (running Linageos)
- Nexus 5x smartphone (stock)
- Samsung Galaxy S5 smartphone (running Linageos)
- Samsung Galaxy Tab S3 (stock)
- Samsung Series 6 SmartTV
- Dell notebook using some broadcom fullmac NIC (Windows 7)
- AWUS036ACH USB stick (Win10)