default or selected kernelversion does not have config value CONFIG_MTD_UBI_DEBUG.
Result is shown for kernelversion 6.2.5

UBI debugging

configname: CONFIG_MTD_UBI_DEBUG

Linux Kernel Configuration
└─>Device Drivers
└─>Memory Technology Device (MTD) support
└─>Enable UBI - Unsorted block images
└─>UBI debugging
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
This option enables UBI debugging.

selects
CONFIG_DEBUG_FS
CONFIG_KALLSYMS