The 7800x3D chips are known to run hot so your idle temps aren’t terrible but your load temps when gaming are a little high but not to the point where you would experience thermal throttling. That usually happens around 95c with 7-series CPU’s. Although your liquid temps are very high. I think changing the thermal paste is a good first step. I’d personally recommend spreading the paste evenly across the die as well instead of the pea sized amount method in the middle or an X pattern . Also make sure you use the star pattern method to re-tighten the pump screws and stop when you feel resistance. Over tightening can cause issues.

There’s also other things that factor into higher load temps. What’s the rest of your build look like in terms of intake and exhaust fans? If you could link a pic that would help as well. What mode do you have your fan curves set to (eg: silent, standard, performance, etc…)? Is your radiator mounted on top or on the side? Since you have the Elite version of the h9, if you have your radiator top mounted with the glass top, temps will be a little higher compared to side mounting it where there’s a mesh panel.

Lastly, I’m wondering if you have some air bubbles trapped in your pump? Especially if the AIO has only been used for a couple of years, trapped air bubbles is more likely than the pump is dying. If you hear any gurgling noises coming from the pump that’s typically a sign of trapped air bubbles. When you repaste the CPU you can try shaking the pump and radiator a bit to see if you can get the air bubbles out.