All 3 values seem very high for RT-AX68UI have the latest firmware and get this:
Temperatures 2.4 GHz: 53°C - 5 GHz: 57°C - CPU: 88°C
<20 devices connected, nothing running on it, AC on in the room
Here
2.4 GHz: 44°C - 5 GHz: 45°C - CPU: 67°C
with 26C ambient
What is the ambient temperature in the room near the router? Is the router free standing on a desk with nothing blocking natural air flow?