Hello, friends. I have discovered the following:

The ER605 router model is released in various countries, and for each country, it appears to have a different firmware version. A few days ago, I updated the firmware of an SMB router, and it stopped working correctly. After investigating, I found out that the equipment I bought is from another country, and I was using the firmware from my country. The router only started working correctly again when I reverted to the original factory firmware.

My question is: how can I accurately identify which firmware for which country I should use, considering that when we buy the equipment, we don't know its origin?