First if hot air is circulating around the Radiator than the liquid will probably be as warm as the air around it. If the air is hotter than normal, the Radiator liquid circulating inside will greatly reduce the heat transfer from the CPU.
Thus I would try to relocate the Radiator so that cool air circulates around it rather than have secondary hot air from the GPU circulating around the Radiator.
Second you have a cheap AIO installed which could be the other issue. It probably is not very efficient at removing heat from the CPU like from more powerful expensive AIO.s
But still make sure the pump is installed correctly on the CPU surface and liquid is circulating. That the Radiator's Fan Air flow is not obstructed in any way and working normally.
See if you can tell a difference in temperature from the Radiator's hose going into the CPU (input) and the hose going out (Output). One should be slightly warmer (output) than the other (input).
Third your processor Maximum Operating Temperature is 95C so you are getting close to the 95C threshold where the CPU will start to automatically throttle (lower the speed).
It really should stay around the mid 70's C or slightly above the 80'C mark under full stress or loads.
So if by relocating the Radiator still doesn't prevent your CPU from running hot under stress than you will need to find a better AIO to install.
Note: you can't damage your CPU from overheating since it has a built in defense that when it reaches a certain temperature where the CPU might get damaged it will shut down the computer to prevent damage.
Running the CPU at high temperatures all the time, above 90C, might shorten the lifespan of the CPU.
