I have been using this router for more than a year, and it was working perfectly without any issues. However, after some time, the device received two OTA updates (pictures attached). Following the updates, the 5GHz WiFi SSID is no longer visible. Everything was functioning properly before the updates were installed.

Please help me resolve this issue. I am unable to downgrade the firmware. I tried to find the same firmware version (1.15.0 Build 250729 Rel.63726n(4555)), but it is not available on the product’s webpage.

Before suggesting that I change or adjust the channels, please note that I have already tried that and none of the changes worked. Additionally, there are now very limited channel options available in the settings. Before the firmware update, there were many channels to choose from. I believe this may be the main cause of the problem.

Please assist me in fixing this issue and restoring the previously available channel options.