Connecting Switches via VLAN Trunk

Office has a gs748t & a xs728t that need to be connected together to pass vlan traffic.  The gs748t then uplinks to a cisco asa 5508. 

I created three subinterfaces on the cisco with vlan 5, 500, 501 (one vlan per sub).

On the gs748t, i created the same vlans.  On the interface (1/47) that connects to cisco, i removed vlan 1.  I then set vlan 5, 500, 501 as tagged members.  To test, on port 1/1, i removed vlan 1, set a port for a vlan (repeated steps for each vlan) untagged, set the pvid to the vlan member.  I can then put device on that port & ping to cisco gw.  Can do this for all three vlans.  Trunk port working properly. 

Repeated the same steps on the xs728t with 1/24.  moved cisco cable to that trunk port & can again ping the cisco gw's from device on that switch.  Trunk port working. 

Next i then created a second trunk interface (1/48) on the gs748t that matches the first one.  I then cabled port 1/47 to 1/23 to connect the two switches together.  

Now i cannot ping the gw or another device from the xs728t over the trunk connection.    Device on the gs748t can ping the cisco gw's.  But i can never get anything to work through the switch2switch trunk.  Even if i swap uplinks between 1/47 & 1/48, the result is only the devices on the local switch can reach cisco gw.  I followed these directions https://kb.netgear.com/11673/How-do-I-setup-a-VLAN-trunk-link-between-two-NETGEAR-switches

All of those trunk ports work fine when the cisco is connected to it.  But do not seem to pass traffic when it's between the two Netgear switches.  

Any thoughts?