slow download and update ?

[Velia]

i been getting slow download for the pass 1 week
and its only on steam only, like watching or downloading from other stuff is completely normal
my speed is 150MB/s(speed test)
and for some reason, my download on steam cannot go to my speed, and its even slower than 200kb/s

i am using lan cabble not wifi
i am using nvme m.2 ussualy its running fine, and i have plenty of storage as well on the drive putting download from other source to the same drive is fine to no slowing down

what i tried to fix it
i change my region to other country
clear chache on steam
log out and login again
clear tempfile
restart router
calling my ISP they say nothing wrong even they put tecnitian to help (change rounter 2 times)

help, please