Hey guys
Sorry for my bad english and my probably noob behaviour.

I have following Setup
An UMTS Router/WifiModem (UMTS) and two TP Link Routers (TPa tl-wa801nd v5.0 and TPb TL-WR841ND) with default openwrt installed (nothing touched, just root password set)

I want to use the TPa as my main router, who takes care of DHCP and FW. The UMTS router should only provide internet and is connected via LAN ethcable to TPa. TPa is also connected to my main computer via LAN. TPa and TPb are should be connected through Wifi and TPb works as a Repeater. TPb is also connected via LAN to another Computer.

What I did
UMTS
I killed the DHCP server on the UMTS, Static IP 192.168.0.1/255.255.255.0 Gateway and DNS Pointing to TPa, disabled the WIFI and connected it via WAN Port to TPa.

TPa
Network -> Interface -> lan -> edit
Static IP 192.168.0.69/255.255.255.0 Gateway and DNS pointing to itself.
Bridge Interface: Vlan Interface (lan) and Wwireless Network are checked
Enable Wifi, set Wpa2 Key and SSID, FW Zone Wan (default), check the Box "lan".

Now I can connect to TPa via Wifi and Lan and everything works fine

TPb
Network-> Wifi-> Scan, Connect to TPa Wifi, enter WPA Phassphrase, FW Zone wlan (default).
Protocoll Client.
Now it askes me to create a new interface "wwan" I assume it is the bridge, so I check the boxes lan and wifi-master.
(and at this point i feel really unsafe)

In network -> Wifi it shows now, that it is connected to TPa

Network-> Wifi-> Add
Creating access point, SSID and Wpa2 set as the same on TPa

TPb is not shown at TPa and if I unplugg the eth cable between TPa and TPb, I can´t connect to TPb via Wifi trough TPa.

I hope I could explain my Problem. Why TPb don´t get Internet even if its connected to TPa via Wifi Client Mod