Internet speed dropping from 400mbps to 60mbps soon after startup.

I recently switched to ethernet because my Wi-fi was super bad with my computer for some reason and I kept disconnecting from games. I connected my brand new cat 6 cable into my MSI motherboard rated for 2.5Gbe but for some reason i'm only getting 60mbps when running my pc normally. I know its not a hardware failure because I get normal speeds when I first start my computer and when i'm in safe mode. I don't know why my speeds are dropping so low and need help since ive tried many things to try and fix it.

List of things ive tried:
– reinstalling Realtek ethernet driver.
– tweaking advanced settings of the ethernet driver
– flushing dns
– winsock reset
– disabling all non microsoft services in system config
– netsh int tcp set global autotuninglevel=normal (same with experimental and the other one, it does nothing)
-other things I can't think of which aren't listed

Things to know
– my link speed is 2.5mbps
– cat 6 ethernet cable
– plugged directly into the modem (not through the walls)
– internet speed subscription is well above 60mbps
– with Rogers internet
– my computer is the only thing having the issue. every other device has normal speeds.
– im plugged into 2.5gb speed ethernet port (back of modem has 4 ethernet ports and 1 is 2.5gb while the rest is 1gb)
– I do not have a LAN manager as far as I know. no MSI center installed (it was previously.)
– in registry editor my network throttling is already at ffffffff hexadecimal
– the device does NOT have power saving mode enabled