How to tackle regenerative current in my H-bridge
The issue here seems to stem from poor layout more than anything. This has been covered by Andy aka, but to compliment what was written BUT more from a powerCore point of view (rather than a sensitive digital point of view, where a solid GND plane &amp; decoupling is pretty much mandatory...)

The H-Bridge is powered from the 24V directly &amp; returns via  GND.

The control is powered from 5V, 3v3 ... &amp; returns via GND, the same GND.This doesn't have to be an issue UNTIL you see the route the return current of the H-Bridge takes... Some of it will start polluting the digital section, especially the bridge on the far right (topside view), Especially considering that bank of via's top left (topside view)

Digi &amp; Power can share the same 0V But you have to be conscious of the return currents. 

Three things I would do


I would clearly separate the Power 0V and the Control 0V and have a single startpoint near the connector 
I would introduce a CM choke between the 24V:GND to produce a 24V_CORE:GND_CORE. this will help block any HF going back onto the sensitive section &amp; equally a similar arrangement from 24V:GND to produce a 24V_CON:GND_CON. Equally consider setting up a Pi filter to help with EMI.
Deal with the regenerative energy.


W.R.T. #3  what is your load inertia? what are your rotor inertia's? what is the deceleration rates?

These three things in conjunction with \$\frac{1}{2}J\omega^2\$ will tell you how much energy you need to pull out of the system. All this energy will be dumped into your DClink (those nice little... 10uF capacitance). THUS with \$\frac{1}{2}CV^2\$ you know how much your DClink will rise.

Then you can decide what todo


reduce your current limit - slows the decel --> exchange of power
reduce your rotor acceleration limit - slows the decel --> exchange of power
reduce your current/speed loop gains - slows the decel --> exchange of power
Introduce a braking circuit


Braking circuit (edit)

During deceleration of the machines rotor+load inertia, you will be pulling energy out of the mechanical system into the electrical system.

Right now you have some MOSFETS that (for argument sake) are switching in 50nS. They are switching 24V ==> 480V/us  

When you start to actively brake/regen two things occur


At higher speeds you will be initially be switching higher voltages: say +10V due to BackEMF &amp; -24V due to inverted H-bridge ==> 680V/us
There will be an exchange of energy: Mech --> Elec


Hopefully it is #1 you are being susceptible &amp; the layout would hint at that. Split 0V plane plus a CM choke &amp; Caps (creating a Pi filter) going to the control should significantly mitigate this - Make sure the starpoint is big enough to cater for the stator current. Equally ensure referencing considerations w.r.t.  IRS2184 FET driver (and Pin#3 or Pin#5 depending on if you have 8 or 14pin variant) 

#2 is a bit different and is only really considered IF you are unable to regen onto the supply. You have a battery so you should be permitted to.  The only complication will come from the leads that connect the battery to your Powercore. 

Say you are using 32AWG, 10m worth &amp; untwisted... This will have a lot of stray inductance &amp; will essentially decouple your powerCore from your supply. Depending on specifics of your system (coming back to inertias and such) you may find your local capacitance is more than enough to absorb this energy with only a slight change in voltage. Worst-case however is you have a lot of energy to remove from the mechanical system &amp; your local DClink rises significantly. 

The stray inductance in your power harness now is a hindrance and your local voltage could rise to dangerous levels. In these instances IF you cannot reduce the inductance or you cannot regen, you would deploy a brake circuit which would dissipate that mechanical energy as heat in the electrical system - a waste. 

A simple comparator circuit that measures the actual DClink (ie at the Hbridge NOT the 24V coming in ). A simple FET+Resistor+Freewheel dide (as the resistor will be inductive...) to then chop the DClink between the voltages of say... 35V:28V.

My gut feeling is you are susceptible to #1 (the difference in dv/dt &amp; your present layout) but for completeness above is a quick overview of resistive regen.