kernel-vanilla: incorrect shim signature

Hi, I am running openSUSE 15.3 and I would like to test the drm-tip kernel branch on my hardware. I am trying to install and run kernel-vanilla-5.17.0-kt.5.1.g401575d from the following repo: https://download.opensuse.org/repositories/home:/tiwai:/kernel:/drm-tip/open... In spite of the package has been installed successfully, I cannot boot due to "incorrect shim signature" at a very early stage. Secure boot is enabled currently. What is the proper way to overcome this problem? I suppose disabling secure boot should help. -- With best regards, Matwey V. Kornilov