Issue with Clover Inject EDID

I finally decided to try and fix my boot screen resolution, which has always been stuck at 800x600. I boot Clover in legacy mode (old motherboard that's not UEFI), and the fix was to tick Inject EDID, Patch VBios, and set the desired resolution to 1900x1200. Works great, except for one thing - it only works if I'm booting from a USB stick. If I use the exact same Clover version and config and boot from my hard drive, it doesn't inject.

This is in my boot log from the USB:

0:100 0:000 LegacyRegion2: Chipset/proc: 0x01008086 0:100 0:000 Next Generation Core processors (PAM 0x80-0x86) 0:100 0:000 Test PAM1=(0x41=90, 0x5a=00, 0x81=11, 0x91=00) at chipset 01008086 0:100 0:000 , Install = Success 2:135 2:035 BiosVideoDriverBindingStart! 2:135 0:000 BiosVideoCheckForVbe 2:135 0:000 EdidOverride not found 2:282 0:146 Edid1- 2:428 0:146 Edid0- 2:482 0:054 0 640x480 attr=3BF - ok, 640x480, working, highest, pref=0 2:484 0:001 1 800x600 attr=3BF - ok, 800x600, working, highest, pref=1 2:486 0:001 2 1024x768 attr=3BF - ok, 1024x768, working, highest, pref=2 2:488 0:001 3 1280x1024 attr=3BF - ok 2:499 0:011 4 1600x1200 attr=3BF - ok 2:502 0:002 5 1920x1200 attr=3BF - ok 2:503 0:001 6 1280x800 attr=3BF - ok 2:503 0:000 BV new mode: 2 1024x768 2:694 0:190 SetMode pref 2 (2) = Success 

But that whole section is missing from my boot log when I boot from the hard drive. I also tried specifying a custom EDID (with the EDID extracted from my monitor), but it still didn't show in the log.

I also note that the USB boot shows this:

7:794 0:000 Starting Clover revision: 4359 on CLOVER EFI 

while, the hard drive boot shows:

0:100 0:000 Starting Clover revision: 4359 on TianoCore.org EFI 

Any idea why one is 'CLOVER EFI', while the other is 'TianoCore.org EFI'? Do you suspect that's relevant? If anyone could help with diagnosing why this isn't working in the one instance, it would be much appreciated!