@Tim49,
We evaluated your issue in details.  Actually we partially reproduced the problem:
Aspose-Warning type 1: Font will be substituted from Aptos to {Arial,Cambria Math,MS Gothic,Gulim,Arial Unicode,SimSun,Segoe UI Symbol,DejaVu Sans,Liberation Serif,FreeSans}
Aspose-Warning type 1: Font will be substituted from Pacifico to {Courier New}
Aspose-Warning type 1: Font will be substituted from Pacifico to {Courier New}
Aspose-Warning type 1: Font will be substituted from Pacifico to {Courier New}
Aspose-Warning type 1: Font will be substituted from Pacifico to {Courier New}
We don’t have Aptos and Pacifico fonts installed. But if I add FontsLoader with the provided Pacifico font, the output changes to this:
Aspose-Warning type 1: Font will be substituted from Aptos to {Arial,Cambria Math,MS Gothic,Gulim,Arial Unicode,SimSun,Segoe UI Symbol,DejaVu Sans,Liberation Serif,FreeSans}
Example:
FontsLoader.loadExternalFonts(new String[] { pathToFolderWithFont });
After testing, we suspect there is a problem with the Palico font installed on your computer.
1). Can you please check if the font is available in java?
    public static void main(String[] args) {
        String fontName = "Pacifico";
        GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
        Font[] allFonts = ge.getAllFonts();
        boolean fontFound = false;
        for (Font font : allFonts) {
            if (font.getFontName().equalsIgnoreCase(fontName) ||
                    font.getFamily().equalsIgnoreCase(fontName)) {
                fontFound = true;
                printFontInfo(font);
                break;
            }
        }
        if (!fontFound) {
            System.out.println("Font '" + fontName + "' is not available.");
            System.out.println("Available fonts:");
            for (Font font : allFonts) {
                System.out.println("- " + font.getFontName());
            }
        }
    }
    private static void printFontInfo(Font font) {
        System.out.println("=== Font characteristics ===");
        System.out.println("Font Name: " + font.getFontName());
        System.out.println("Font Family: " + font.getFamily());
        System.out.println("PostScript Name: " + font.getPSName());
        System.out.println("Size: " + font.getSize());
        System.out.println("Style: " + getStyleName(font.getStyle()));
        System.out.println("Bold: " + font.isBold());
        System.out.println("Italic: " + font.isItalic());
        System.out.println("Plain: " + font.isPlain());
    }
    private static String getStyleName(int style) {
        switch (style) {
            case Font.PLAIN: return "Plain";
            case Font.BOLD: return "Bold";
            case Font.ITALIC: return "Italic";
            case Font.BOLD + Font.ITALIC: return "Bold Italic";
            default: return "Unknown";
        }
    }
2). Can you also provide us with additional information:
OS version
JDK version
additional fonts (if installed)
3). If possible, can you provide a docker file that allows this issue to be reproduced? (This will allow us to say with 100% certainty that the cause has been found and corrected.).