Model : TL-WR1043ND

Hardware Version :

Firmware Version :

ISP : Networx Bulgaria

Hello,

I have a few questions:
1.
I have bought a new http://www.tp-link.com/us/products/details/cat-5506_TL-WR1043ND.html (here is the version of my country Bulgaria - http://www.tp-link.bg/products/details/cat-9_TL-WR1043ND.html)
and its hardware version is EU/4.0, that what it says on the back of it, but I can't find firmware for that version for my country.

When I visit the site for my country ( http://www.tp-link.bg/download/TL-WR1043ND.html) and select V4 for hardware version it does not show any files for download.
If I visit the site for en, there is no even firmware version 4.0 ( http://www.tp-link.com/us/download/TL-WR1043ND.html)

Am I missing something here or there is some issue on the site?

2.
The reason I am looking if there is new version of the firmware, because the speed of the router is very unstable.
When I restart it, for the first 5 minutes it works very good, but after that the internet is slow.
I have to wait for seconds(5+) to load any website on the internet.
I tested the internet cable directly wired to my laptop and had no any issues, this happens only when Im on the router.

3.
I think the router is gigabit (that what it says on the box and in the site), but when I connet to it in the network options in Windows 10, the connection is not 1Gps, but 150Mbps,
is there some configuration for that in the router? or there is some other thing that I am missing?

Regards.