Can't convert IMG to ISO

So I'm currently working on my own OS (just for fun), and it's currently being compiled into an IMG file. I know it's not needed but I would like to try and compile it into an ISO, but so far I've had no luck with it. I'm not quite sure which files are needed, so just ask for them and I will edit the post :)

When I run the img I get this:

But when I run the ISO I get this:

Here's my compile script I wrote in batch:

@echo off

echo Building KronkOS floppy image!
echo.
echo Assembling bootloader...
echo ======================================================
wsl nasm -f bin bootloader/boot.asm -o bootloader/boot.bin
echo Done!

echo.
echo Assembling KronkOS kernel...
echo ======================================================
wsl nasm -f bin kernel.asm -o KERNEL.BIN -l kernel_list.lst
echo Done!

::echo.
::echo Creating elf kernel file...
::echo ======================================================
::wsl nasm -f elf32 -o kernel.o kernel.asm
::wsl ld -m elf_i386 -o kernel.elf kernel.o
::del kernel.o
::echo Done!

::echo.
::echo Assembling programs...
::echo ======================================================
::cd programs
::    for %%i in (*.BKF) do del %%i
::    for %%i in (*.ASM) do wsl nasm -O0 -f BIN %%i
::    for %%i in (*.) do ren %%i %%i.BKF
::cd ..
::echo Done!

echo.
echo Adding bootsector to disk image...
echo ======================================================
wsl mformat -f 1440 -B bootloader/boot.bin -C -i images/KronkOS.img
echo.
echo Done!

echo.
echo Copying kernel and applications to disk image...
echo ======================================================
wsl mcopy -D o -i images/KronkOS.img KERNEL.BIN ::/
wsl mcopy -D o -i images/KronkOS.img programs/*.BKF ::/
wsl mcopy -D o -i images/KronkOS.img programs/*.BAS ::/
echo.
echo Done!

echo.
echo Do you want to build and ISO?
echo ======================================================
choice /c YN
if errorlevel 1 set x=1
if errorlevel 2 set x=2

if "%x%" == "1" (
    cd images
    wsl genisoimage -input-charset utf-8 -o KronkISO.iso -V KRONKOS -b KronkOS.img ./
    cd..
    echo.
    echo Done!
)

echo.
echo ======================================================
echo Build done!
choice /c YN /m "Run KronkOS build in QEMU?"
if errorlevel 1 set y=1
if errorlevel 2 set y=2

if "%y%" == "1" (
    if "%1" == "-d" (
        wsl sh -c "export DISPLAY=0:0 && qemu-system-x86_64 -s -S -fda images/KronkOS.img"
    ) else (
        if "%x%" == "1" (
            wsl sh -c "export DISPLAY=0:0 && qemu-system-x86_64 images/KronkISO.iso"
        ) else (
            wsl sh -c "export DISPLAY=0:0 && qemu-system-x86_64 -fda images/KronkOS.img"
        )
    )
)'
cls

So I changed the tool I used to convert it into an ISO from fat_imgen to mtools.
I also followed what Michael Petch suggested in a comment which was to use the -cdrom option in qemu, and now everything seems to work as it should.