Getting fired too often in manager career in FC24

I would definitely recommend that you play at least 50% of the matches as a manager. That will not only boost your manager rating but also improve your players overalls as well. Something I noticed is that the players are being taught via AI how to play and they learn from how YOU specifically play. That said, the more matches you simulate, the less your players will be able to adapt to certain situations. Also you should always keep an eye on the "Objectives" that the board have created for you within the central tab. If you are not meeting your boards objectives then your manager rating will become very low, and you ultimately will be fired or less desirable on the job market. Hope this helped!