There IS a BIOS setting you need to check that can cause this issue, and it is an obscure item not often mentioned in instructions. Background: with that AIO system (like most) the design is that the PUMP should always have a full 12 VDC power supply from its header so it always operates at full speed. Control of the CPU temperature is done only by altering the speed of the RAD FANS according to the temperature sensor inside the CPU chip.
Here's the quirk that can cause a problem. There are two basic designs of fans: older ones with 3 wires (and holes in their connectors) have their speed controlled only by reducing the Voltage supplied to them; newer ones with 4 wires (and holes) should receive a fixed full voltage supply PLUS a new PWM signal from Pin #4 that the fan uses to control its speed. Because both are available, many mobos (including yours) offer on most of their fan headers an option to set the header CONTROL MODE. This is the detail of which electrical signal set is sent out to the fan on the header to achieve the speed required. They also offer an "Auto" option for this item to make it simple for users to ensure that the correct signals are sent out to whichever fan design is connected, and that is usually the default setting of a header. What that actually does at every start-up is run a test of the fan's response to PWM signals. If that does reduce the fan's speed, OK. If it does not, then the header switches to the older Voltage Control Mode to force the fan speed to change when needed.
Now, the PUMP of your system is designed electrically just like an older 3-pin fan, and that type can NOT use the PWM signal to change its speed. So when that pump is connected to the CPU_FAN header (or another) that uses this Auto detection system, it is found to be an "older 3-pin fan" and the header changes to reducing the Voltage sent out to force the "fan" to run at a lower speed. That is exactly what we do NOT want for the PUMP - it is supposed to run full speed all the time! Running at reduced speed reduces the cooling capacity of your AIO system. So there IS a way to fix that with a BIOS setting.
If you don't have it yet, get the BIOS Setup Guide for your mobo here
https://download.gigabyte.com/FileL...e_0104.pdf?v=cfbe0375700835184b0adf38304d004b
See p. 2 on how to enter BIOS Setup (you may already know this). For your mobo, the best connection system would be to plug the PUMP 's 3-hole cable into the mobo CPU_FAN header, and the RAD FANS (via their Splitter) into the CPU_OPT header. See your manual p. 4 for the Main Menu, then use the F6 key to get to Smart Fan 6 on p. 6. At upper left you select which header you are adjusting. Make these same settings at upper right for BOTH the CPU_FAN and CPU_OPT headers
CPU_FAN Speed Control to Normal - do NOT set to Silent
Fan Control Use Temperture Input to CPU IF this option exists for these headers - it may be set this way akready and you cannot change
CPU_FAN Control Mode to PWM, not Auto or Voltage
CPU_FAN Stop to DISabled so these items can never stop
CPU_FAN Mode to Slope
CPU_FAN Fail Warning to ENABLED so you WILL get a message on-screen if ever the pump or rad fans fail
When you have all your fan headers adjusted, use the BACK button at bottom right to return to the Main Menu. There hit the F10 key to get to the Exit Menu (p.25) and choose Save & Exit Setup. This will save your new settings and reboot.
Set up this way, your pump will run full speed all the time as designed (spec is close to 3200 RPM). The Rad Fans will have their speed adjusted continually according to the temperture inside the CPU chip. The speed signal of the pump will be monitored for NO signal, whcih would indicate it has failed. If that ever happens you will get a warning on screen and it probably will shut down your entire system soon afterwards, even without waiting for the CPU temp sensor to show high temps. This is to protect the CPU from rapid overheating with NO cooling if the pump fails. ONE of the rad fans also will be monitored for failure similarly, but not all of them can be monitored. So from time to time YOU should just look and verify that all rad fans are working.
All this should ensure your AIO cooling system works properly, and may reduce the CPU temperture. Be aware that the max temperture spec for this CPU is 95C, and that the Cyberpunk test is intended to get the CPU working hard. So 80C under that workload is quite acceptable. If you find that, under those high load conditions the RAD FAN speed is still NOT at full speed (2450 RPM max spec), then your system actually COULD cool more but does not think that necessary.