I’ve had the same issues plus gradual disappearance of thunderbolt ports functionality for a couple of years. And I resolved those all just today by replacing the original ports with couple of ones from AliExpress. To be honesty, I was afraid to completely break the device, and when I booted after replacement and have still been seeing same issues, I’ve thought “at least it is alive” and go for a rest. After a couple of hours without any resetting of SMC or PRAM it shouted up the fans (silence! finally!) and gradually kick up the ports so I finally can use HDPI 4K@60Hz, full-speed external hard drives and firewire audio interface via thunderbolt. It is epic win for just a $20! \ 0 /