linhkienbodam,
Thank you for your inquiry.
Its hard to make a positive troubleshooting diagnosis from a single picture. But it is possible that there is some issue with the sweep timing. Description of this can be found in section 5.8 of the owner manual. https://www.furunousa.com/-/media/s...manuals/821841_operators_manual_version_g.pdf. You will need to access the installation manual to make this adjustment.