Better find out what is going wrong with the printer. Maybe some WiFi option that has been set that it does not support. It may help to update the printer. Anyway, you can download 6.47.4 for your router (MIPSBE version), upload the file to the router, and then select "downgrade" under sy...

After upgrade the firmware to 6.47.7, the wifi connection shows the sign padlock to all computers. The computers can access the Internet as normal, but the wifi printer cannot print, it shows printer offline. As I trust the Mikrotik I missed to backup the configuration. How can I downgrade to 6.47.4...