Booting into recovery mode shows blue Recovery Booting text, then gets stuck with a black screen Phone: Samsung Galaxy S4
Android: 4.2.2 / XXUBMGA

I am on djembey's pre-rooted slim XXUBMGA.

Recovery Mode does not work for me. From OFF mode, I press Vol Up+Home+Power. Then, I see a small blue "Recovery Booting..." text in the top left corner of the screen, but nothing happens. It stays black. If I stop pressing the three buttons, the phone boots normally.

Download mode works for me (VolUp+Home+Power), and I am able to flash using Odin.

How do I fix the recovery mode? Do I need to flash stock recovery again? Would I lose my data if I do so?

Similar question:
Blank screen when trying to boot into recovery mode on Samsung Galaxy Tab 2 10.1
When small blue writing appears, let go of just the power button. It should then boot into recovery. Source.

Disclaimer: I am DLAddict on XDA.