lennox coil freeze up

I am having an issue with a lennox evaporator coil m#cx34-36c-6f-2, it is attached to a lennox furnace model# EL296uh090xv36c-05. Both were installed in 2014. The issue is that every couple of weeks the coil freezes up, unit stops cooling.

Once defrosted the suction pressure never goes above 100 psi, and with 410a that is low enough for it to freeze. The txv was replaced, and the results were the same. The issue appears to be air flow, as the super heat and subcooling at the outdoor unit are good.

The air filter is clean and there are no obstructions in the duct work. I increased the airflow setting in the lennox wall thermostat/ controller to 1400 cfm from 1050, in an attempt to move more air. The LCD readout on the furnace says that it is moving 1400 cfm of air, but listening to the noise level of the furnace it sounds like the blower is moving at half speed. I put an ecm motor tester on the motor and with the tester the ESP reading was the same. .44

I have yet to find any documentation from Lennox where with an actual live esp reading can be compared to a chart, so the readout can be confirmed that is the actual amount of air the furnace is moving. Could it be possible that the fan motor is not turning fast enough even though the board appears to be sending the proper signal for the motor to ramp up to it's highest speed? Like I previously mentioned the external static is the same where the motor is hooked to the furnace's circuit board, or an ECM tester. Thanks to all