If you don’t make changes in the Wavlink extender network for a long time, you might face slow working. Or there can be an issue like the Wavlink extender not working if there is outdated firmware of the extender. Also, there can be some other causes apart from outdated firmware. But, to get rid of this issue, you will need to check the entire network of Wavlink and its advanced wireless settings. To check this, go to the Wavlink web interference and access its web management window and verify the frequency bands, bandwidth channels, security encryption, and many other things. 

Then, try to set a new password for the network after changing it and add some special and numeric characters to it. Then, verify some external factors like the placement of the extender, signal interruptions, connectivity between devices, and others. In the end, check the firmware updates of the extender and update it if there is a new version available. Reboot the extender and check the working now as the issue will resolve now once you use these tips.