Mudi gl-e750 5G antenna not working?!

I have issues with the 5G antenna and I don’t know why.

The wifi is visible but the connection is unstable and it drops constantly. Sometimes the router will selfreboot but it will not fix the issue.

How can I troubleshoot it?

I opened the router and the antennas and the modules are fixed well enough.

I wonder if this is not a software issue?

Can you try the firmware 3.201 from GL.iNet download center

Not sure if it is software problem and how it is related to 5G.