Macbook Pro starts at a decent speed but after a bit it is stuck at a low speed
I'm using a Macbook Pro running Mac OS X 10.14 with two GPUs (Intel HD Graphics 630 and Radeon Pro 555). Unfortunately, of all the computers I have, this is the fastest setup I have.

When I start hashcat running on both GPUs, I get a reasonable speed of 50K WPA hashes/sec. However, after it's been hashing for a while, it gets stuck at 3K WPA hashes/sec. Both GPUs go at a significantly lower speed, not just one of them.

I've tried pausing hashcat and even waiting hours (when the system is a normal temperature) before resuming, but it is still stuck at 3K WPA hashes/sec. It seems the only way to get back to normal speed is to quit hashcat and start a new instance.

Any idea how to prevent this from happening? Thanks
Please post the command line you are using