Yes, you can have too many CPU cores - Ampere's 192-core chips break ARM64 Linux kernel in two-socket systems, company requests higher core count support
by from Latest from Tom's Hardware on (#6GS6R)
Data center CPU manufacturer Ampere has requested to boost the default Linux CPU core count from 256 to 512 to support its latest AmpereOne CPUs with core counts of up to 384 cores in dual-socket configurations.