OK, it seems that you were right about the cs priorities.... I only started by changing the CS to what I think it would be best after your explanation and this is how I left them:
iptables -t mangle -N dscp_mark
ip6tables -t mangle -N dscp_mark
iptables -t mangle -F dscp_mark
ip6tables -t mangle -F dscp_mark
iptables -t mangle -A FORWARD -j dscp_mark
ip6tables -t mangle -A FORWARD -j dscp_mark
## icmp gets CS1
iptables -t mangle -A dscp_mark -p icmp -j DSCP --set-dscp-class CS0
ip6tables -t mangle -A dscp_mark -p icmpv6 -j DSCP --set-dscp-class CS0
## game traffic for rocket league?
iptables -t mangle -A dscp_mark -p udp --sport 1:442 -j DSCP --set-dscp-class CS5
ip6tables -t mangle -A dscp_mark -p udp --sport 1:442 -j DSCP --set-dscp-class CS5
iptables -t mangle -A dscp_mark -p udp --dport 1:442 -j DSCP --set-dscp-class CS5
ip6tables -t mangle -A dscp_mark -p udp --dport 1:442 -j DSCP --set-dscp-class CS5
iptables -t mangle -A dscp_mark -p udp --sport 444:65535 -j DSCP --set-dscp-class CS5
ip6tables -t mangle -A dscp_mark -p udp --sport 444:65535 -j DSCP --set-dscp-class CS5
iptables -t mangle -A dscp_mark -p udp --dport 444:65535 -j DSCP --set-dscp-class CS5
ip6tables -t mangle -A dscp_mark -p udp --dport 444:65535 -j DSCP --set-dscp-class CS5
## SMB Share transfers
iptables -t mangle -A dscp_mark -p tcp --sport 445:445 -j DSCP --set-dscp-class CS1
ip6tables -t mangle -A dscp_mark -p tcp --sport 445:445 -j DSCP --set-dscp-class CS1
iptables -t mangle -A dscp_mark -p tcp --dport 445:445 -j DSCP --set-dscp-class CS1
ip6tables -t mangle -A dscp_mark -p tcp --dport 445:445 -j DSCP --set-dscp-class CS1
## web y youtube
iptables -t mangle -A dscp_mark -p tcp --sport 80:80 -j DSCP --set-dscp-class CS1
ip6tables -t mangle -A dscp_mark -p tcp --sport 80:80 -j DSCP --set-dscp-class CS1
iptables -t mangle -A dscp_mark -p tcp --dport 80:80 -j DSCP --set-dscp-class CS1
ip6tables -t mangle -A dscp_mark -p tcp --dport 80:80 -j DSCP --set-dscp-class CS1
iptables -t mangle -A dscp_mark -p udp --sport 443:443 -j DSCP --set-dscp-class CS4
ip6tables -t mangle -A dscp_mark -p udp --sport 443:443 -j DSCP --set-dscp-class CS4
iptables -t mangle -A dscp_mark -p udp --dport 443:443 -j DSCP --set-dscp-class CS4
ip6tables -t mangle -A dscp_mark -p udp --dport 443:443 -j DSCP --set-dscp-class CS4
#Nintendo Switch TCP
iptables -t mangle -A dscp_mark -p tcp --sport 443:443 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --sport 443:443 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --dport 443:443 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --dport 443:443 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --sport 6667:6667 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --sport 6667:6667 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --dport 6667:6667 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --dport 6667:6667 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --sport 12400:12400 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --sport 12400:12400 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --dport 12400:12400 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --dport 12400:12400 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --sport 28910:28910 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --sport 28910:28910 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --dport 28910:28910 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --dport 28910:28910 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --sport 29900:29901 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --sport 29900:29901 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --dport 29900:29901 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --dport 29900:29901 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --sport 29920:29920 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --sport 29920:29920 -j DSCP --set-dscp-class CS2
iptables -t mangle -A dscp_mark -p tcp --dport 29920:29920 -j DSCP --set-dscp-class CS2
ip6tables -t mangle -A dscp_mark -p tcp --dport 29920:29920 -j DSCP --set-dscp-class CS2
after this change the internet is ok and everything working normally, I still have to test gaming but for now everything works SQM included.
I will be doing some tests and see if it fails, now I wonder if the dscp was working correctly in the DIR835 xD