Can't change default exporting format

[Denise30545554d98m]

So, I export a lot of mp4 videos with h.264. But one time, ONE TIME, I promise one time, I exported an mp3 audio file, and now every time I need to export a video it is preselected mp3 as exporting format, and I have to manually change to h.264 video every time, I've exported more than 20 videos after that, or more, but still have mp3 as default, I have exported A LOT of mp3's by error 😅
What can I do?