Slushpool is fine there's nothing wrong with this pool.

Anyway, you can try ckpool you can find their official thread from here https://bitcointalk.org/index.php?topic=1876330.0

Or Kano pool official thread from here https://bitcointalk.org/index.php?topic=789369.0

They are both good.

If changing pool doesn't work can you try this below?

Changing fan speed to 90 to 100% then set the frequency to 550m then test the miner again.

To find the secret menu where you can customize the fan speed and frequency follow this step https://bitcointalk.org/index.php?topic=2690140.0