Can't get 99% adobeRGB coverage on U2413

Hello,

I got a (refurbished) replacement monitor from Dell after contacting them regarding low contrast ratio issue that yumichan figured out from my earlier post: http://en.community.dell.com/support-forums/peripherals/f/3529/t/19652479

After connecting the replacement unit, I ran a few calibration (Native and adobeRGB) with i1Display Pro + DCCS and verification dispcalGUI.

I did the same thing as before:

1. Factory reset monitor

2. Disassociated all ICC profiles in Windows (I run Windows 7)

3. Calibrated with DCCS 1.5.3 (newer version couldn't "find" my display)

a. For "native" calibration, I manually entered RGB x,y taken from EDID generated with dispcalGUI; WP 0.313, 0.329; 120 cd/m; Bradford, Version 2, Table based; Large patch set

b. For adobeRGB, I simply selected the preset from drop down menu; and the rest was same as "native" calibration

4. Verified results with dispcalGUI 3.0.4.3 (latest version)

a. RG_Phosphor for correction; verify_extended.ti1 testchart

d. I made sure the ICC profile was set as default in Windows; "Current" was chosen under Settings in dispcalGUI

The results:

1. Native: https://www.dropbox.com/s/f3wycy6hynpuzbk/Measurement%20Report%203.0.4.3%20%E2%80%94%20DELL%20U2413%20%40%200%2C%200%2C%201920x1200%20%E2%80%94%202015-10-01%2014-36_Native_D65_DCCS_Cal1%20%28R%29.html?dl=0

2. adobeRGB: https://www.dropbox.com/s/kbvob84lmxjgfal/Measurement%20Report%203.0.4.3%20%E2%80%94%20DELL%20U2413%20%40%200%2C%200%2C%201920x1200%20%E2%80%94%202015-10-01%2016-41_adobeRGB_D65_DCCS_Cal2%20%28R%29.html?dl=0

The contrast seem okay, a lot better than previous unit and passed all recommended tolerance. Then I ran a "Profile Only" in dispcalGUI for the "Native" calibration using these settings:

This is what I got:

When I did the same thing with the previous U2413 unit (the one with low contrast than usual), I would get 100% and 99% gamut coverage for sRGB and adobeRGB respectively.

I repeating the steps a few times and still receive similar results. According to a post by yumichan I read before, these Dells shouldn't have gamut coverage issue. What am I missing here?

Please help. Thank you.