so I think your CPU is possibly degraded. the problems show up when the voltage is lower and that’s consistent with your report. I had instability when the processor transitions from higher to lower voltages mainly.
seems like that’s why compile crashes.
compile is a very bursty workload
ecc support is pretty good since ages 1.2.0.0 on am5. been using 48gb udimms without issue. steel legend does it, pro art x670/b650 does it, etc.