i'm so socially awkward with my close friends how do I stop

Okay so like I've noticed that every time I get close to a friend, I suddenly just become really socially awkward?? Like I have this one friend I'll call Luci. We’ve been friends since our sophomore year of high school, and now we’re both college freshmen. So, we’ve known each other for quite a while and are basically twins when it comes to our interests. We have the exact same taste in music (we’ve had the same top five Spotify Wrapped artists for the past 3 years and text regularly about music we think the other would like), clothing style, haircuts (bc of our very similar outward appearances we have even been called twins by middle aged women a lot and its funny every time LMFAO), hobbies (pretty much just playing the same video games and dealing with college life), and even same sense of humor. 

But anyways despite all this in common, it still hasn't helped me in my interactions with her when we hang out. For background info, Luci moved to a very far state for college last year and I stayed in our hometown so we only really have conversations through texting 4 times a week and call occasionally to play video games. This past week I ended up flying to her city to attend a concert with her as again we love the exact same artists and to explore the city together. While the concert was very fun (mostly because it was spent screaming our butts off), the time spent outside the venue waiting for the concert and in the city felt... off. For some reason, we just couldn’t find anything to talk about. And this is someone I have so much in common with, so it’s confusing??

It’s like, on paper, we’re carbon copies of each other, yet when we’re together, it feels like we hit a wall. Sometimes we can talk non-stop for hours, but only when there’s something specific to talk about—like gossip or something new that's happened in our music/gaming world. When we don’t have that, it’s like, nothing. We’ll go to cool places and do fun things, but there’s this weird, uncomfortable silence that kind of lingers the whole time. Don’t get me wrong, I’m all about comfortable silences, but when it goes on for hours, it just feels… you know… awkward? And I know this isn't because we don't like each other because we always have SO much fun in our texting conversations and when we're playing video games. I just feel so awkward when we haven’t talked in like 10 minutes while hanging out.

I really don’t know what goes wrong when we hang out guys. Is there any way I can help fix my social awkwardness and overall conversion starters?