So, I dug a bit deeper into this, and had the opportunity to have a conference call both with Meraki Support, as well as Microsoft Azure Support. It seems that the main reason why I couldn't get ClientVPN to work was because ports 500 and 4500 were being blocked. I was not able to open those ports by applying an NSG, due to a vendor policy from Meraki on the vMX RG. Also, it seems that the Public IP SKU being deployed from the managed app, was randomly being chosen as a "Standard" IP SKU, which apparently has some default port blocked. If the deployed IP SKU is "Basic" ClientVPN will work. The only way around this, is a redeployment of the vMX.. I'll probably add some more on this, after I've done some more testing, and sharing these results with Meraki Support.
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