I have the same issue some people are getting here, I have seen no solution so here is my case.
I've got this "Promise Technology Pegasus3 R6 Mac Edition 24TB 6-Bay Thunderbolt 3 RAID Array (6 x 4TB)".
I've tried mounting it on a Macbook Pro 2017 15" on it's usb-c ports with no success.
I have treid downloading every single driver from the support page, even though the firmware is getting me in trouble, becasue it says "Image not recognized" (image attached), so I have not been able to install.
The Promise Utility works though, but it shows no signal from the Hard drive.
The button is always red.
This is all the information I have so far!
I will appreciate your help! Thanks in advance.