Not Asus, but on 4 other models it looks like 89C is max reached during testing on AMD 23.4.2 drivers: https://www.techpowerup.com/review/amd-radeon-rx-7600/36.html
Here's a Asus 7600 Strix OC at 77C on default BIOS and 81C on quiet BIOS along with what appears to be updated tests of the above: https://www.techpowerup.com/review/asus-radeon-rx-7600-strix-oc/36.html
If you have Adrenalin, check that the Max GPU Clock Frequency isn't set higher than the card's specification. If it is, set it to the card's max and see what temps are like. This was the case on my XFX RX 6800 and I had to manually set it to 2100 MHz.
I wouldn't be surprised if paste or thermal pads weren't properly applied either. If the GPU clock is normal, that might be worth looking at next.
You can also do a simple undervolt to lower temps. I was able to reduce my RX 6800 from 1025mV to 935mV.