I'm not sure whether this is a question for the workplace or IPS board, but I think it's more of a inter-personal than work related issue. Please correct me if I'm wrong.
About three months ago I started working for a rather big software company right after finishing university. I'm the only female (26 years old) fulltime engineer (there are two other female students, who are there a few times a week, but in a different team) in my department (the others are all about 25-40 years old with a few exceptions). I have no problem working with men, as i have dealt with a male dominated environment in my studies, too, and many of my close friends from that time are male. During my studies I have encountered some... awkward situations, with male students not knowing how to handle a female team mate or even lead, but nothing even close to harassment or anything. So it's not like I never experienced any feeling of exclusion because of my gender, but it hasn't bothered me much at that time, because the projects were short-lived.
Now, in the working world, this is a bit different. My department is settled in R&D, so we are actually quite a few small teams with very different projects, that have not really much to do with each other. I'm in a very new, very small team, with only one colleague, who I get along with quite fine. So I don't really work with the other people in my department and we generally don't have much in common work wise.
Now, the thing is, that I can't really integrate into the rest of team somehow. I'm generally shy at first, but quite outgoing as soon as I'm in a conversation with someone (I might even talk a little bit too much at times, when I'm excited about a topic...). At first I thought, that it's probably going away with time, when I get to know them better. Now, three months into the working world, I still have the feeling, that they don't really know how to interact with me. I don't think this is mainly because of my gender, but I suspect it's at least a part of the problem. They are definitely not unfriendly or rude or anything, but some of them can't even look me in the eyes, when I greet them in the hallway, and oftentimes it's just really, really awkward (for both sides I assume). In the beginning some of them tried to talk to me out of courtesy, asking about my studies and my project, but this stopped after about a month, when these subjects were exhausted. The atmosphere is generally really chill, relaxed, and easy most of the time, and they talk to each other quite frequently and most have been working here for a few years by now, so it sometimes feels like I'm left out of the "boys club", when they talk about their projects, their hobbies, ... When I try to just take part in the conversation (e.g. through asking questions) it oftentimes feels like hijacking, because I don't really have to say anything about the subject and feel that I sound just desperate and annoying. They also had no problem interacting with a new colleague who started after me, who was integrated right from the start (he was working in a bigger team, though).
I have to say, I didn't really mind that much first, because I did not intend to make any best buddies here, and I thought it would just become better with time on it's own. But now my only team member is away for a long vacation. On most days the whole department is having lunch together. I really dread the lunch time by now, because they mostly won't talk to/ignore me (not in a mean/hostile manner, just like... not waiting for me to get my food and such. More like in an awkward manner.) and sometimes when the table is already full I have to sit alone. I often try to start a conversation on the way to the canteen, to keep it going during lunch, asking about projects, current events, and so on, but mostly it won't last until lunch, because we oftentimes spread out to get our food and meet again at a table.
I really want to integrate myself into the department more, to avoid such awkward situations in the future and have a more pleasant/healthy work environment for everyone. But I really don't know what to do anymore. I tried initiating conversations, I tried asking questions, making jokes, and generally try to be as likable as possible (this is my nature anyway). Oftentimes these strategies work for a single conversation, that is then really great. But afterwards it's just like before and they still have a hard time interacting with me later. Is there anything else I can do? I'd rather not talk to my lead about it, at least right now, because I fear it would be taken the wrong way, me complaining about them not liking me immediately and that it's their fault and such (which I don't believe at all). If possible, I want to do this on my own by adjusting my communication to be more inviting.