Change from kernel-tai (RTAI) to kernel-rt (preempt-rt). Kernel-rt is the free of charge version of SUSE Linux Enterprise Real Time. Kernel-rt provide Preempt-rt patches for linux kernel.
https://wiki.linuxfoundation.org/realtime/start
Read chapter “Kernel and Version requirements”:
https://linuxcnc.org/docs/stable/html/getting-started/system-requirements.html
Never, never install a linux kernel which is not supported by SUSE with security updates!
See row “openSUSE Leap 15.5” for a overview of all supported linux kernels from SUSE: