Model : Archer C1200

Hardware Version :

Firmware Version : 2.0.2 Build 20180118 rel.38979

ISP :

Firmware Version: 2.0.2 Build 20180118 rel.38979
Hardware Vesrion: Archer C1200 v2

Hello. I have a problem logging in to the router for at least a few days. I restored the factory settings which unfortunately didn't help. The problem is that after pressing the "Zaloguj" (Login) button I am not logged in to the router. No matter if you enter the correct password or not, after pressing "Login" for half a second is a gray icon of charging and then disappears and nothing happens, I can click "Login" indefinitely. I have it on all devices, on different browsers.
I don't know what could have caused this problem, only recently everything worked and I didn't make any changes to the router.
The problem is shown in the following gif, which I recorded:
https://i.imgur.com/3YdnsNp.gifv


Thank you in advance for your reply and help.