I work in a team of 10 people, we are all around the same age (mid 20s). I have a male colleague who is really nice but I think he does treat me differently to our other colleagues.
One example is when we had our assessments with our manager he specifically said in front of everyone (including our manager) in a meeting that I was ready for my assessment and that I was doing really well (I definitely wasn't doing well as I was still really new and still being trained - at first I thought he was trying to sabotage me but I now understand through subsequent conversations that he genuinely thought I was doing well). Another time, I was training a new colleague and he told them I'm great and they will learn a lot by working with me. In the break room if ever there are treats brought in by our manager and I don't grab one as I sit down he will come and bring me them and will always check whether I've had any to make sure they don't all go before I have had the chance to have some (not in a controlling way, just in a nice way). He is always making sure I take all of my breaks. All nice things.
He has recently had a promotion so now is more senior and he moved departments. He came over and told my supervisor how lucky she is to have me in her team and how great I am completely out of the blue. He has done this a couple of times now. There was also a period of a few weeks where my workload was doubled as my colleague was absent and there was no cover. I was doing fine but struggled to take all of my breaks and he noticed and when I said it's fine, it's just a temporary busy period and I don't mind he raised it in a meeting with the managers to ensure that it didn't happen to me again.
I can't tell if he's just being nice or whether there is more to it.