Your problems are because of the B9S Chainloading in Luma. Go to MaxConsoles. search for "gateway payload converted to b9s". The best option for a payload is there, however, it won't boot through Luma. But it will run fine through BootCTR9. You'll have to go to maxconsoles on your own as I don't think I can link it.
Use the "
gw payload converted for b9s" from Maxconsoles along with the
B9S compatible BootCTR9
https://gbatemp.net/threads/release-the-bootctr9-release-thread.435347/ To boot GW. It's a cleaner setup than the one commonly linked to here.
That should boot the red card. No blue card needed.
11.2 EmuNAND will not work online however or run a few of the newest games. IF you want to run GW online will need to update MOST of your EmuNAND. There is a
tutorial here on doing it using NUSD.
https://gbatemp.net/threads/how-to-get-11-4-emunand-working-on-gateway-with-online-access.472624/
The
tutorial was written when 11.4 was newest but there is an updated file list on page 9 for 11.6 titles. Or you could go to YouTube. Search "Nintendo 3DS GATEWAY EmuNAND on lasted firmware" (typo is in the actual youtube title)
a user there already has all the .CIA files in a pack and a user from the temp has done this method. Either of these methods will result in a 11.6/11.4 hybrid EmuNAND which will run all games and go online fine in GW Mode.
Your Blue GW Card isn't necessary to boot the Red Card but can still play NDS games like a champ. If you don't see the icon make sure the SD is inserted right and has all the right files on it.
If I were you, I would back up the blue card SD to PC. reformat in FAT32.
MUST BE FAT32. Go to the Gateway-3ds homepage. Download the old
3.7.2 beta firmware there on the
downloads page. Copy the contents of the
Blue Card (R4i) folder to the SD root. Then move your ROMS and .SAV files from your Blue Card Backup to the root too. Homebrew too if you use it. This way you have a fresh start.
Also, if you are feeling brave, you could try the multi-kernel! Search for "
playing gba with blue card" on Maxconsoles. Only the newest version on there still has a good link but that's good enough. The Multi Kernel is capable of running a few emulators from a handy boot menu on the Blue GW! I snipped the list below.
1.NDS ROM: Multimedia is Moonshell 2.10 & select *.nds will automatically load wood 1.62, put your rom in any directory(suggest root)
2.GW Installer:Run this software to crack 3DS.Insert the GW red card to run 3DS game.
3.GBA Emulator:load /__rpg/Apps/patch.pat as a patch,then choose a *.gba in any directory,press A until the game runs.
4.FC Emulator

ut your game into root:/SNES/,choose one in the emulator.
5.Other Emulators:Choose one game in the emulator then run it.Games can be put in any directory.
6.Cheat DB:Put a UTF-8 USRCHEAT.DAT to/__rpg/
cheats/
The GBA roms work well using this method on my N3DS with the blue GW. I would like to add that while I use GW for extra storage too, GW does carry risks if you run it in SysNAND mode. Don't ever do that. GW has inferior protections. You could wind up on latest firmware with no b9s. Or bricked. It's good to have a NTRboot device handy just in case. (some blue GW cards DO work with NTRboot but not all) Also if it asks you to input a button combo to boot to SysNAND at boot, hit
power.