the ping initially was normal and after about 30 mins, the ping jumped to 500 to 1000ms and never goes down. tried to reset and the same issue occurs after about 30 mins.
Are you pinging the extender itself, the router or an internet server? To isolate the issue, you should start by pinging the extender, then move to the router and finally to the internet.
Also, are you seeing packet loss on the pings, or are you just seeing an increase in the ping time?
High ping times are usually caused by queuing delays in the devices on the network path. Packet loss/retransmission on the wifi links will create queuing. Network congestion will also, so it's possible that one of the links on the network path is being overloaded. Many devices (particularly internet servers) make responding to ping a low priority task, so it is also possible that the device you are pinging is busy doing some other task.
