E5-575G-55KK Samsung T3 SSD is only doing 30MB/s read/write when it should be up to 450MB/s.

I have an Acer E5-575G-55KK. I bought a 1TB Samsung T3 SSD. It is supposed to do 450MB/s but I am only getting 30MB/s read/write.

I have it connected through the USB-C port via a Belkin Thunderbolt cable (which defaults to USB-C on non-Thunderbolt devices). I tried using the supplied USB 3.0 cable on the 3.0 port and the speed was even lower.

Samsung support site says "T3 supports the max speed of 450 MB/s in the Windows 7 (or up) PC environment with USB 3.0 and UASP Mode support."

I looked online and an article told me to check in Device Manager under "Storage Controllers" for "USB Attached SCSI (UAS) Mass Storage Device". I did and it is there, however, when I talked to Acer support they said my laptop doesn't support UASP. The rep didn't seem to knowledgeable though.