Ok, we know the sensor is not the likely culprit here since it's been replaced twice. Assuming of course they are replacing the bank 2 sensor and not bank 1 by mistake. It's more common then you might think.
Anyhow, this leaves the possible issues to be either the fuel pump, the fuel injectors on that bank or possibly intake air leaks.
That being said, since the truck idles good I don't think you have any intake leaks, so I would focus on the possibility that the truck has a fuel pump issue or a problem with one or more of the fuel injectors not spraying properly on that bank. It is possible that what you are feeling at higher speeds is caused by a drop in the fuel pump pressure. This would have to be driven with a pressure gauge on the fuel line to determine if it's the cause or not.
Bank 2 is the driver side, just for clarity. Also, the mass air flow sensor can cause a lean fuel mixture, so the shop that is trying to repair this for you should monitor the input from the mass air flow sensor. If it's out of range it can cause this without setting a code for itself. I have seen this in the past as well.
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Thank you so much!