Region : Argentina

Model : TL-WA5210G

Hardware Version :

Firmware Version :

ISP :

We have a TL-WA5210G on a mountain, directly connected to a 'internet per radio' system by a 10m ethernet cable.
The power suply it given through 100m cable (of 1.5mm²) directly from a solar system of 12V.
In the valley, about 100m distance and about 40m lower in level of terrain I have a TL-ant2409A connected to my ultrabook through a LogiLink USB Wlan adapter.
There is direct eye-contact between the antenas, but many trees all arround.
This set-up worked absolutly fine during several month. It always established connection quickly and had full performace of out internet provider.

Suddenly things changed without making any change in config or recognizing other changes.
Now the TL-ant2409A is not connecting to the TL-WA5210G anymore when being in the valley. Going up on the mountain, close to the TL-WA5210G I gets connection and full performance. Going down with turned on ultrabook it maintains connection but performance drops drastically. Once deconnecting it is not connecting again.
The ultrabook and other notebook are able to connect to the TL-WA5210G with the internal WIFI system, but allways with very low performance.

Which problems might create the dificulties?
How can I find out?

Thanks for you atention
Achim