Ignition’s Modbus driver doesn’t have any support for these 32-bit registers because they aren’t part of the Modbus spec. The only way to read a 32-bit value with the Ignition driver is to combine two 16-bit registers into a 32-bit value, which is what happens when you select Int32 or UInt32 datatype.
Try changing the driver setting of “Reverse Word Order”, and possibly “One-Based Addressing”. What you show in the modbus scanner doesn’t correspond with the data shown in the Ignition tag browser.