Hello Sir/Madam --

I believe this problem is not new, but I've never been able to figure out the exact rules for it, so please bear with me.

I bought a new TPLINK A7 WiFi router -- henceforth just 'A7' for brevity.

I connected it (using wired Ethernet cable) to the "Main Router" -- which is a TPLINK C4000 A20.

I logged in successfully for the first time -- typing 'tplinkwifi.net' on the MS EDGE browser URL.

I then configured initial setup parameters:  Dynamic IP >> Don't clone MAC addr >> assign SSID >> password.  Then the A7 reboot.

After the reboot, I tested the wireless and it all worked perfectly. 

I waited for at least 20 minutes, testing 1 laptop 1 PC and 2 smartphones.

All worked just fine.

Now I wanted to get back into the A7 for a second time -- and this time 'tplinkwifi.net' failed.

The message I always got back -- Chrome or MS EDGE browser -- was "too long to respond".

I note that I am still using a wired mode of access into the A7 -- i.e., a CAT6 Ethernet cable from my laptop to one of the LAN ports of the A7.

I tried the "direct" way of getting in:  typing 192.168.0.1   or  192.168.1.1  and these also failed.

My past limited exposure to this routine procedure involved a rather old but perfect condition DLINK 615.

Knowing the DLINK's IP as 192.168.0.1, I would use a wired connection as always, change my laptop's IPv4 configuiration to

an IP address if 192.168.0.2, subnet mask = 255.255.255.0 and then type 192.168.0.1 into the browser URL.  Always worked.

But in trying this approach with a brand new (received 3 days ago, Jan 26) TPLINK A7, it wouldn't work.

I've cleared the cache/history of the browsers used, rebooted my laptop each time just to be sure, etc.  and still no luck.

I must be missing something,  

Please help ... any auggestions, tips or guidance is highly appreciated.