2.5gb internet port?? + usb problems

[veryneedy]

i have a TERRAMASTER T9-450 9Bay NAS running 5.1.145

i brought this nas 1 month ago and noticed straight away it seemed very slow compared to my other one which is
TERRAMASTER T9-423 9-Bay running same op I have no apps installed on either and only use it as a storage unit for my plex media

I have several terramaster extension boxes TERRAMASTER D6-320 External Hard Drive Enclosure and TERRAMASTER D5-300C USB3.1 as soon as I plugged in them into the new nas t9-450 I noticed the CPU went straight up to 75-80% and stayed there for quite a while also after 24 hrs the nas becomes unusable and just freezes and I cant get into it I have also attached a pic showing where I managed to catch it crashing and will only free itself if I unplug the USB and wait 1 min or so in case it was a problem with a hard drive in the external hard drive or the unit its self I changed them around with the older nas and it will still crash with a different USB unit and different drives

in comparison the t9-423 has no problem with the same enclosures plugged in and the CPU will only go up to around 25% whilst plugging in the USB items I have also tried the most sensible things like new USB leads and no difference

my 2nd problem is I upgraded my 1gb unmanaged switch to 2.5 hoping this may help or even give better speeds I am currently getting around 280mb upload speed to the nas my PC has 2 2.5gb lan ports so it made sense to upgrade the switch but for some reason, its made no difference to the speed
I am sure there's no settings I need to change is this correct it should just detect it ??

i am using all cat 8 cables and have also brought new ones to make sure the switch is also telling me it detects the 2.5gb and everything is plugged in correctly this is happing with both machines both running on there own network cat 8 wires straight from my PC 2.5gb to the switch 2.5 and straight into lan 1 on the nas any help I would be grateful or should I contact support

thanks for your time

[veryneedy]

sorry forgot to attach pic