@DudenDude For configuring your WA801N in AP mode you could use this guide. I would recommend to set WA801N with a static IP address and its DHCP server off to avoid any IP address mismatch.

@Akbar010202 Check the "Operation Mode" menu - if there's no "Range Extender" mode then use the WDS feature to extend your wireless coverage: Here's a guide on that.

@Akbar010202 This error message means that the FW file you're using to upgrade is not for your device HW version or FW region. Device HW version or FW region can be seen on the device bottom sticker....

@Hoffy Follow the Tether FAQ - Q4/A4 and Q9/A9 for more details when using tether app. You can test to login the router via web browser and see if the password you've set is correct. Check this FAQ...

@Chinesedonuts49 A DHCP lease time of 120 min is perfectly normal - disconnects are most probably due to other reason. Regarding your second question check this post.

@Hoffy Here's a guide on how to configure a router with the tether app. Administrative password should not be longer than 14 characters and should not include any spaces.