I cooked 3 pieces of scotch fillet steak which had a lot of thick fat running through it. I cooked it for 2 hours at 54 Celsius. It was reasonably tender but definitely not medium rare. More medium. I thought that 2 hours was the correct time to cook a steak? It didn’t sear well at all so my first meal was a disaster. My husband asked if I could return it 
Two hours is fine for steak, although scotch fillet, being from the chuck primal can handle a bit longer than some other steak cuts.
Time is for texture. Temperature is for done-ness. So, if 54C was too done for you then reduce the temperature. Below 54C is fine for 2 hours.
You might also do well to confirm the temperature of the water bath with another thermometer to make sure that your APC is as accurate in its readings as it should be.
Make sure you dry the meat before you sear it. If it is still wet it has to boil off the moisture and you will not get a good sear.
54°C should be closer to rare than to medium, so I echo the recommendation to verify the water temp with a thermometer. Also, what was your searing procedure?
As others have suggested, what is your searing procedure including the time you do the searing?
With my set-up, I will usually do steaks in the APC at the very minimum of 124F/51C for really rare but then the finish searing will bring it up a bit to the upper side of rare.
Delphi, the Scotch Filet steak is the continuation of the rib eye towards the animal’s shoulder. There’s a couple of good steaks in the chuck where it was separated from the prime rib section. There should be no thick fat running through the steak if it has been properly cut. I suspect you got something else. Cooking at 54 C should have resulted in steaks on the rare side of medium rare.
Depending on what you actually got I would have cooked that at 55 C for as long as 12 hours.
As others suggest, you likely need to monitor the actual cooking temperature you have and work on your searing technique.
I’ll try again tonight. Its very annoying that I have to check that the temperature is correct? Thank you for all your comments
Delphi, don’t be annoyed. It’s a self defeating practice.
I’ve learned to trust everybody and everything, but to be really successful i also check on them. You need to know what’s really happening, not what you hope is happening.
Never accept a filet that has a lot of fat running through it. It’s not what someone says it is.
Make it a habit to check everything, it will soon become a life-long habit.