Steam download keep droping to zero

Hi, i'm actually desperate making this post, i wanted to install Tekken 8 but every time i stop the download and restart it the connexion start fine with like 200Mbits but after around 5 seconds it drop to zero and then go again but with a slow speed like something between 12~30 Mbits and if i let it download it goes to zero and restart every 5 seconds, my download should have took between 1 and 2 hours but because of this i'm 5 hours later and tweaking so i'm begging for help, for any more info, i'm french and so my download region is ( i tried to change to an area wher its 3Am but still the same problem), i'm installing it on my secondary SSD

Edit

After an experience, it start to go from 0 when the download speed arive around 100 Mbits