First off: 140kg deadlift / 95kg squat is slightly unbalanced, but not tremendously so. I have at times had a 100kg squat when able to deadlift 140kg. So it's worth looking at but not necessarily pathological. It's also still not clear where exactly the two lifts diverged in your progression scheme, which is key information.
A few possibilities:
You might have good anthropometry for the deadlift. This seems unlikely - long torso and short femurs is ideal for the squat, whereas the deadlift is easier for those with comparatively long legs. Addressing this simply means squatting more and maybe always squatting relatively less than you deadlift.
Some people consider the deadlift to need less volume to progress than the squat. Since you're doing roughly similar amount of work for each of the deadlift and squat, it's possible that you are simply pushing your deadlift better.
To fix this I'd just try 5 sets of the squat, and optionally dropping the deadlift to 1 set to make room for other exercises, possibly including a brief squat, maybe done light.
You could have a technical error or mobility issue with the squat. Diagnosing this would require form checks.
With the rate of progress you report I wonder if you're running into a mental block with the squat. It's an intimidating lift. In contrast, the deadlift – perhaps especially sumo style – presents much less psychological pressure, so I wouldn't expect you to be hitting the same wall there yet.
If you worry about the squat, or are hesitant to add weight to the bar in a way that you're not with the deadlift, this could be it, or one element of the problem.
Solving a mental block with the squat demands squatting a lot. Make it your best friend. Make your squat form something people compliment out of the blue. Squat every day, and squat with a bar every time you can. Most importantly, as you approach the bar for every set, conclude decisively that you are going to smash it. And then smash that bar with every rep. Attack the squat with more certainty as it gets heavier each week.
Your lifts & bodyweight being what they are, it's also possible you're simply at that stage where adding weight to the squat requires a qualitatively different kind of effort.
I suspect this might be the problem because 95kg is right where relatively athletic men your size often first experience adversity in the squat. It's where the lift stops being a challenge that can be overcome by blindly pushing a little harder. This happens later with the deadlift. But squats with errors (like a good-morning'd squat) often stop working-without-thought around this relative weight (a little more than bodyweight). That's when you have to actually lift the weight correctly or it will not work. I've noticed in myself and other guys roughly my size (80±3kg, 180±5cm) encounter it circa 100kg, maybe 115kg if they're really risk-inclined and stubborn. It's different for everybody but doing it wrong stops working around this stage.
Fixing this requires a mix of basically all the prior fixes. You have to dial in your mobility, and your form, and your mental game, and you have to squat more often. Build a really reliable squat and then you should be able to add weight.