Friend/ partner chooses to spend time with friends over me

TLDR: partner/friend keeps choosing to spend time with friends rather than talking to me and I don’t know if something else is going on.

22(M) have been friends with and dating for some time my friend/partner, for privacy reasons I’ll call Mia 22(F), for over for years now, dating for 2 of them at the start of the relationship but decided it was best to be friends after that.
Recently me and Mia have gotten back together, mainly from me asking her out ask I needed a lot of time to find myself and make sure that this was right for me. I waited so long because I wanted to give her an opportunity to either find someone and end things between us or to continue things between us. I asked her out about a month ago and since there things have gone kinda pear shaped.

Whenever we were friends right before it, we would have a pretty standerd routine of me going to work and her going to work, talking through out the day, maybe a call whenever she is on her break, and then a call at night whenever we both go in. For the record, we don’t live together as I moved away for uni a year into our relationship. We have been wanting to live together for some time now and I finally managed to find a place for the both of us to live together which is close to my work and close to places for her to work as she can get transferred pretty easily. However, ever since we got the flat confirmed, she has been making less and less time for me, to the point where now we would send a few messages a day and maybe a call for 5-10 minutes at night because I have to get up early. This issue is that I have told her on several occasions that I don’t mind her going out with her friends as I understand she is moving, but that I do mind that I am finding it really difficult to message her and speak to her.

She would usually go out with her male friends from work, one of which she was interested in seeing how things went, before I asked her out. I haven’t ever meet this person besides seeing him once or twice at her work and her telling me about him from nights out they have together with their other friends. This would lead on to her going out with this person and maybe one or two other people to go out on drive at night pretty frequently and then going to their house to chill and chat, but this would go on till 00:30 at night our later since she gets out of work at 23:30, and the entire time she wouldn’t message me or really keep me updated as to how things are going.

I have spoken several times to her about this and how all I need from her is to just send me a couple of messages and have a quick talk about how our days have been, but this has ent resulted in anything useful as she would always go straight back to not messaging me. It’s gotten to the point where I’ve explicitly told her that this is the issue and that I’ll be okay if she messages me but she seams to have an issue with that and I don’t understand why.

The reason why I’m so confused is that we are so close at times, very open with things, tell each other I love you and so on. So I don’t understand why this is going on. And this whole conflict has lead to us needing some space and a couple of days to know what we want, this was mainly her wanting space and time to think as we had an argument because it happened again and I wanted up on her for over half an hour to sign some documents for the accommodation.

What I’m wondering is if there is something else I should be worried about, or if it’s time to move on because this is happening near everyday and I just feel is getting further and further apart. Am I just being stupid and not seeing that there is something going on with her and her friends? And what would you recommend I do to fix this as things always manage to come round as being my fault and that I have done something wrong, I don’t think I’m being unreasonable by asking to just speak to her a few times when she is out, or am I?

Sorry for the poor grammar, English isn’t my strong point.