It was prior to the march 2.4 update, then the change after. I assumed it was because you moved the portrait image away from the top left and just had it as the civ image on the right bar where you select civs. Maybe that's why? No idea.
Typically when I would use an fotor AI generator to generate images, or at the few times I used yours, it would create two files, one in Leader FGs and one in portraits. Since I had used photoshop to correctly size the AI generator images I made with Fotor, I saved the final png files to the appropriate folders (portrait, leaderFG). I didn't save the master PSD files because I thought I was done with those civs. A few of the Civs I made were actually mods, with custom racetraits, etc. Those were unaffected as their associated image files were built into the MOD.
After the update, none of the custom images I made that were manually put into the leaderfg folder from Fotor and photoshop, nor the AlientGPT ones from the game were present. They were present in the portrait folder, which was weird. Since the protrait is typically a smaller section of the leaderFG, I didn't have a chance to rebuild them. I did have the fotor images within that site, but... I didn't have a way to just redo the images on a custom civ, I had to rebuild the entire civ. I think a way to just update the images on the civ might have made it easier on me, then again, how could your alienGPT choose images without that text and a complete rebuild. I set up a back of the factions folder as a hedge against future changes. I have rebuilt some of the civs I had, about 35 or so. Mostly starting over. I love the game and mod it extensively, I've never shared the mods but I've been pretty creative with it. You can do alot more than you could with GC3 IMO. Sorry for the rant, but if you were me, you'd have a large sigh at having to rebuild so much. Cheers.