To fix the Wavlink AC1200 WiFi range extender issues try or consider the below or lower solutions. 

Try to place the Wavlink AC1200 WiFi range extender at the central or halfway location of the office and house. With new wires replace all damaged wires. Discard all the extra Wi-Fi-containing gadgets. Improve the software of the Wavlink extender from time to time. Try to turn off the Wavlink AC1200 extender. If these above tips don’t help you to fix the Wavlink AC1200 extender issue then try the last or final method to remove the issue. 

Reconfigure Wavlink AC1200 Extender 

To do the Wavlink AC1200 setup process, reset your extender. 

Initially, press the Wavlink extender reset button by hairpin. By doing this all the AC1200 Wavlink extender LEDs will turn off. Thus, it means your device is now completely reset. 

Hence, doing all the above solution tips the Wavlink AC1200 extender issue is now fixed.