I'm experiencing the same problem. I've stopped using 2019 because of this. Even simple cuts only interviews with no effects take 5 to 6 times longer to export H264 compared to 2018. I have the latest Radeon Drivers
MacBook Pro 2.9GHZ i9, 32GB 2400 MHz Ram, Radeon PRO 560X 4096MB, Intel UHD Graphics 630 2536MB, High Sierra
I'm experiencing the same problem. I've stopped using 2019 because of this. Even simple cuts only interviews with no effects take 5 to 6 times longer to export H264 compared to 2018. I have the latest Radeon Drivers
MacBook Pro 2.9GHZ i9, 32GB 2400 MHz Ram, Radeon PRO 560X 4096MB, Intel UHD Graphics 630 2536MB, High Sierra