TTF_RenderGlyph_LCD doesn't work with transparent background

[leoncounter]

I created a simple program to render the character 'A' in the top left corner of a window. I've set the foreground to be completely white and the background to be completely transparent. When using TTF_RenderGlyph_Solid, TTF_RenderGlyph_Shaded, and TTF_RenderGlyph_Blended, everything works correctly. When using TTF_RenderGlyph_LCD, the glyph appears to be completely transparent. If I use an opaque background, it renders correctly, but using the fully transparent background makes even the foreground transparent.

Result when using TTF_RenderGlyph_Shaded:

Result when using TTF_RenderGlyph_LCD:

Here's the code:

#define SDL_MAIN_USE_CALLBACKS 1
#include <SDL3/SDL.h>
#include <SDL3/SDL_main.h>
#include <SDL3_ttf/SDL_ttf.h>

static SDL_Window* window;
static SDL_Renderer* renderer;
static TTF_Font* font;
static SDL_Texture* glyph_texture;

SDL_AppResult SDL_AppInit(void** userdata, int ac, char** av)
{
	if (!SDL_Init(SDL_INIT_VIDEO))
	{
		SDL_Log("sdl init error: %s", SDL_GetError());
		return SDL_APP_FAILURE;
	}
	if (!SDL_CreateWindowAndRenderer("Glyph Test", 800, 600, 0, &window, &renderer))
	{
		SDL_Log("window/renderer creation error: %s", SDL_GetError());
		return SDL_APP_FAILURE;
	}
	if (!SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_BLEND))
	{
		SDL_Log("unable to set blend mode: %s", SDL_GetError());
		return SDL_APP_FAILURE;
	}
	SDL_SetRenderVSync(renderer, 1);

	TTF_Init();
	font = TTF_OpenFont("DejaVuSans.ttf", 128);
	if (!font)
	{
		SDL_Log("unable to open font: %s", SDL_GetError());
		return SDL_APP_FAILURE;
	}

	SDL_Color fg = {255, 255, 255, 255};
	SDL_Color bg = {0, 0, 0, 0};

	SDL_Surface* glyph_surface;
	//glyph_surface = TTF_RenderGlyph_Solid(font, 'A', fg);
	//glyph_surface = TTF_RenderGlyph_Shaded(font, 'A', fg, bg);
	//glyph_surface = TTF_RenderGlyph_Blended(font, 'A', fg);
	glyph_surface = TTF_RenderGlyph_LCD(font, 'A', fg, bg);

	if (!glyph_surface)
	{
		SDL_Log("unable to render glyph: %s", SDL_GetError());
		return SDL_APP_FAILURE;
	}

	glyph_texture = SDL_CreateTextureFromSurface(renderer, glyph_surface);
	if (!glyph_texture)
	{
		SDL_Log("unable to create texture: %s", SDL_GetError());
		return SDL_APP_FAILURE;
	}
	SDL_DestroySurface(glyph_surface);

	return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppIterate(void* userdata)
{
	SDL_SetRenderDrawColor(renderer, 127, 127, 127, 255);
	SDL_RenderClear(renderer);
	float w, h;
	SDL_GetTextureSize(glyph_texture, &w, &h);
	SDL_FRect dst = {0, 0, w, h};
	SDL_RenderTexture(renderer, glyph_texture, NULL, &dst);
	SDL_RenderPresent(renderer);
	return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppEvent(void* userdata, SDL_Event* e)
{
	switch(e->type)
	{
		case SDL_EVENT_QUIT: return SDL_APP_SUCCESS; break;
	}

	return SDL_APP_CONTINUE;
}

void SDL_AppQuit(void* data, SDL_AppResult result)
{
}

I've tested with other fonts and had the same result, but here's the ttf file used just in case.

font.zip

Currently using fully up-to-date Arch Linux, SDL 3.2.28, FreeType 2.14.1, and using Sway 1.11. GPU is AMD 6600 XT with Mesa 25.3.2.

I tried using SDL3_ttf-3.2.2 and building from main, but did not notice any changes.