For the problem of not being able to access the management page.
- Please try again to press and hold the reset button for 10 seconds after the router starts to restore the factory settings.
- Re-upload the official firmware through uboot, refer to the document:
What should I do if my router is bricked - GL.iNet Router Docs 4
We cannot help with abnormal behavior caused by installing third-party plug-ins.
Regarding your DDNS loss issue, if it is convenient, please export the log for us to analyze.