Multipath rules not working as expected

 Hello community, 

I have two WANs setup this way:

All users are on one signle subnet, including some servers. Now these server hosts are included in a Network group "Servers" that i created. 

I have Two multipath rules set-up this way (both by "Interface Persistence"):

- The First one specifies that the "Servers" group uses the secondary WAN to get out, and i have the "Skip rule on interface error" option checked for WAN failover.

- The second rule is for the rest of the users which specifies for them to ONLY use the primary WAN with no failover, so i have the "Skip rule on interface error" unchecked.

Whenever i unplug the secondary WAN, the "Servers" group switches automatically to using the primary WAN as expected but, when i turn off the primary WAN all the users skip to using the secondary WAN even though i unchecked the "Skip rule on interface error" option. i don't know what am i exactly missing here. Any suggestions?

Thanks!