If anybody can help it would be much appreciated as I'm all out of ideas.
My laptop has a PCIe 4.0 port and I'm using a BEAST EXP GDC V8.5c with a Radeon RX6700 xt card but it does not show in device manager. The card lights up and fans slightly turn but then remain stationary. Prolonged testing makes the GPU heat up and I have to stop. I have a chunky dell power supply but I've been using a Corsair RM850X instead as there was no difference in progress.
As said, if anybody can help I'd be so grateful as I've spent too much time on this somewhat lost cause.
My opinion is that External PCIe dock doesn't support the latest AMD GPU cards.
Found the website Blog for EXP GDC but version 8.0: http://exp-gdc.blogspot.com/2015/12/exp-gdc-beast-laptop-external.html
It shows all the Nvidia and AMD GPU cards that are compatible:
All of AMD GPU cards are Non-Supported by AMD anymore.
Make sure you have all the cables connected correctly from the laptop to the EXP GDC Dock including any PCIe GPU Power cables.
If I were you I would contact EXP GDC Manufacturer Support and ask them if the Dock supports the latest AMD GPU cards or not.
EDIT: At the same website as above it mentions which Laptops aren't compatible: http://exp-gdc.blogspot.com/2018/05/exp-gdc-compatibility-support-list.html
Since you didn't mention the Make & Model of your laptop here is the total list of compatible Laptops:
Now the above list is for version 8.0 and it probably is out-dated. So I still suggest you open a Support Ticket and ask them if the latest AMD GPU cards are compatilbe and if your laptop is compatible.
Personally I believe either your laptop or GPU are not compatible with your PCIe Dock from EXP GDC.
In Device Manager, click "View -> Show hidden devices" - check if the GPU is listed there. It may show errors if there are any. You can also right-click it, "Uninstall device" and select to remove drivers. Then reinstall the drivers.
If that fails, there shouldn't be many parts to troubleshoot: GPU, enclosure, enclosure's port, power cable, usb cable, thunderbolt port and the laptop itself.