Hi Harry,
This may be a batch issue. If both of your tanks are from the same batch, it could be a problem with the chip that allows the printer to read it properly (the amount of room it has to accept the ink).
Also, is it a genuine tank AND the correct tank? Sometimes 3rd party items may have these problems.
The last suggest is that the chip reader on the printer may be bad (unfortunately). If an authorized service center around you is able to check it and has access to the chip reader, it "may" not be that much. Can always confirm this with Epson direct if needed, but you should be able to get a replacement from the place you purchased it from or Epson will cover if it's their product and never used before. They usually have a 1-year warranty on supplies.
Hope one of these helps you and you get it resolved!
IT Supplies