From your reply, I could tell you are an experienced manager who knows what it usually takes to win against tougher oppositions, and when you won another match-up comprehensively, so probably it is a troll match with the other 1-0 loss.
So the question left would only be:
With matches where you have a significant advantage when you almost always win by your usual tactics to outscore.
The engine now decides to troll you by dyfunctioning the best 2 or even best 3 attackers of your team and make them miss every single chances and/or just change to a setting where your team would not score from direct open plays with hard attacking, attacking or even normal mentality. Then what kind of changes with your current team setup with your subs can change the whole formation, orders, player lines, players positions and every other thing possible to score that important goal?
The above question is not a criticism at you, but one which I will ask myself when pre-planning what players to buy and build to compliment the existing squad so to at least draw those troll matches. Hope it makes sense.