I’m a little out of my depth here, but if I’m reading the screenshots right, your P cores are running at ~5.5GHz (which is good) but your E cores are running at ~1.4GHz (which is really slow). Have you changed any settings manually? If so, how did you change them?

Can you post more HWInfo screenshots with more stuff displayed? For instance, can you expand the Core Clocks and Core Effective Clocks drop-downs and take another screenshot when running Cinebench?

I’d guess the problem is this:

My power consumption seems fine and sits around 240-250W

An unconstrained 13900k will easily draw >350W. (See this link for power levels and this link for corresponding Cinebench scores.) Remove the power limits and test again, and keep an eye on your thermals. If your temps at stock power levels are already ~90C, then thermal throttling might be your next roadblock once you remove the power limits.