40mb/s max transfer rate on nvme SSD (USB 3.1)

Having issues getting above 30-40mb/s transfer rates using a caddy (this one and another):

https://www.scorptec.com.au/product/hard-drives-&-ssds/enclosures/86167-orico-m2pv-c3-bk?gad_source=1&gad_campaignid=21594915999&gbraid=0AAAAADsuegPIU74oYp_QXCBcCmmD0KGo_

I want a fast on the go mini external SSD and have two NVME drives sitting around, both less than 2 years old, light usage and from two different companies (both are capable at around 3000mb/a read, 1500mb/s right)

In crystal disk mark and in basic read right (3gb file) and I max out at between 40 and 30 mb/s, slower than the 120mb/s my old spinning 3.5" HDD transfers at.

I've tried the NVME drives in both USB C 3.1 ports on my surface pro and also on bother the USB C and USB C 3.1 ports on my desktop.

I've tried a few different cables, one short very thick cable from a HDD and another which is capable of pulling 240w, so surely data bandwidth isn't the issue?

I think I've exhausted all avenues so hopefully someone here can help