how to fix high dpc latency issue on my loq rtx5050 ryzen 7 250 laptop

Your LatencyMon results point to two main culprits: nvlddmkm.sys (NVIDIA's kernel driver) with a highest DPC execution time of 3581 µs, and Wdf01000.sys (Kernel Mode Driver Framework, tied to your NVIDIA webcam/USB devices) with the highest ISR time. Combined with LatencyMon's own note about power management, this is a very common pattern on Lenovo LOQ laptops with hybrid Ryzen/NVIDIA setups — it's almost always power-management and driver related, not hardware failure.

Try:

Set Windows power plan to Best Performance / High Performance

Go to Settings > System > Power & Battery > Power Mode, and set it to Best Performance (plugged in). Avoid Balanced or Power Saver modes when doing latency-sensitive work — they aggressively throttle the CPU and cause the DPC spikes LatencyMon flagged.

Disable CPU/PCIe power-saving states (C-states) in BIOS

Reboot into BIOS (usually F2 or Fn+F2 on Lenovo LOQ) and look for CPU C-state control or 'Global C-state Control' — disable it if present. Also check for any 'PCIe ASPM' or 'Power Supply Idle Control' setting and set it to Typical Current Idle rather than Low Power Idle. This directly addresses the power-management cause LatencyMon named.

Update BIOS/UEFI firmware

Check Lenovo Vantage or Lenovo's support site for your exact LOQ model and download the latest BIOS. Lenovo has pushed several BIOS updates specifically fixing power-state and latency bugs on Ryzen+NVIDIA LOQ models.