2.5gbe adapter only negotiating to 2.0gbps according to iperf and networkctl

Hello people, im trying to figure out why this usb adapter is only linking at 2.0gbs, its a realtek chip using 8152 driver, yet ethtool reports the newer 8156....ive heard that linux would select the first available driver that is compatible with the device, even if theres a new one..Could this be tha case? ive tried different cables and ports, yet the same adapter can saturate the link at 2.5 (iperf tested) on both windows and mac..heres a snap of the info, any guidance is appreciated : Link File: /usr/lib/systemd/network/73-usb-net-by-mac.link Network File: n/a State: n/a (unmanaged) Online state: unknown Type: ether Path: pci-0000:00:14.0-usb-0:1:1.0 Driver: r8152 Vendor: Realtek Semiconductor Corp. Model: USB_10_100_1G_2.5G_LAN Hardware Address: 00:e0:4c:9e:35:a3 (REALTEK SEMICONDUCTOR CORP.) MTU: 1500 (min: 68, max: 16362) QDisc: pfifo_fast Master: vmbr1 IPv6 Address Generation Mode: eui64 Number of Queues (Tx/Rx): 1/1 Auto negotiation: yes Speed: 2Gbps Duplex: full Port: mii