ECMP Load Balancing Issue

Hi guys hope you can help with this one.
I have the following setup. RB1000 functioning as a load balancer, it is set up with 2 different ISP’s on 2 ethernet ports. I then use the mangle to mark routing port 80 ,110 ,443 and 25 (per traffic load balancing). My routing table’s 0.0.0.0/0 route for port 80 then has 3 gateways(ECMP) as my one isp is running at 1mbps and the second at 4mbps the gateway for the 4mbps ISP is in twice giving me a ratio of 2:1.
The problem is that this works great for a while but later a simple site like google just doesnt come up. After refreshing a couple of times it comes back ok. Can this be a dns issue? The two ISP’s obviousely use different DNS servers.

Mangle

1 ;;; HTTPS 443 Traffic
chain=prerouting action=mark-routing new-routing-mark=HTTPS 443 passthrough=yes protocol=tcp dst-port=443

2 ;;; HTTP Traffic
chain=prerouting action=mark-routing new-routing-mark=Route HTTP traffic to ECMP passthrough=yes protocol=tcp dst-port=80

3 ;;; FTP Traffic
chain=prerouting action=mark-routing new-routing-mark=Route FTP traffic to ECMP passthrough=yes protocol=tcp dst-port=21

4 ;;; POP Traffic
chain=prerouting action=mark-routing new-routing-mark=POP3 traffic passthrough=yes protocol=tcp dst-port=110

Routes

add comment=“HTTPS Traffic LB1” disabled=no distance=1 dst-address=0.0.0.0/0 gateway=172.168.0.1 routing-mark=“HTTPS 443” scope=30 target-scope=10
add check-gateway=ping comment=“HTTP Traffic ECMP LB1//3” disabled=no distance=1 dst-address=0.0.0.0/0 gateway=172.168.0.1,172.168.4.2,172.168.4.2
routing-mark=“Route HTTP traffic to ECMP” scope=30 target-scope=10
add check-gateway=ping comment=“POP3 Traffic LB2” disabled=no distance=1 dst-address=0.0.0.0/0 gateway=172.168.0.1,172.168.4.2 routing-mark=
add comment=“Default Route EVERYTHING ELSE LB2” disabled=no distance=1 dst-address=0.0.0.0/0 gateway=172.168.0.1 scope=30 target-scope=10 “POP3 traffic” scope=30 target-scope=10

Ok I removed the one WAN (ISP) that is giving us 4mbps and replaced it with the same ISP that we currently have (meaning all WAN ports are from the same ISP now) and it now works ok. Could this be the ratio that I am using or the DNS for that ISP? Has anyone used different ISP’s when load balancing with ECMP on a Mikrotik?

seems like that another ISP has bad quality of service %)