Strange inter ping issues

I am currently using a FS526Tv2 with three Vlans configured on it. 16(staff), 66(public), 99(maint). Vlan 16 on my network is 172.16.0.0/20 Vlan 66 is 10.66.0.0/16 Vlan 99 is 172.16.0.0/24. I am using one router splitting up the vlans going into the switch at three different ports. Vlan 66 can ping all other vlans how ever vlan 16 can not ping 99. I have 3 GS108Ev3 spread out throught the office all of which are on vlan 99 but configured to run vlan 16 on 6 of the 8 ports. Vlan 66 can ping them and even access them via web but vlan 16 can not. Will provide anymore information if needed. 

p.s i did not set this network up, i came in to it.