Dumb Routing Questions! My auxiliary switch (on a different floor) cannot route to my firewall (which is also my wireless controller)

Alright so, I'll preface this by saying I am by no stretch a network admin - but my company doesnt have one.

I'll try to be as concise as possible here. All HP procurve switches. VLANs in question are MGMT and WIRELESS.

 

I have a core switch, connected to the firewall.

On the core I have a number of vlans -- MGMT, WIRELESS will be relevant for my question here. (to note, there never used to be an MGMT vlan - if you wanted to manage a switch you had to be physically at it - I added the MGMT vlan, and can now talk to all the switches from my desktop computer)

From the core switch, I can ping the firewall, and my wireless access points can communicate to it as well to get their IPs, and do wireless controller-y things.

 

I have my vlans tagged on trunk ports that run downstairs across fibre to the switch for that office space. MGMT and WIRELESS vlans are configured on the downstairs switch as well (and tagged).

From my downstair switch, I can ping my core switch - but cannot ping the firewall, which means my AP cannot get an IP/be usable. The AP was working until relatively recently -- only change I can think of is the implementation of the MGMT vlan and a route 0.0.0.0 to x.x.100.10 (mgmt IP of core switch)

Not sure what I need to add/modify/remove to make this work properly... Any help is appreciated!