After 4 years of FWB/friendship, we became exclusive now I don’t know how to interpret her behavior

I 30m have known this woman 26f for around 4 years. We started as friends with benefits, but it was never only about sex. We had a genuinely good connection, a lot of fun, conversations, affection, and we spent time together doing normal things as well.
Over the years there were different phases, including around a year with very little contact, but we still remembered important dates and eventually reconnected. This year she initiated meeting multiple times, came to visit me three times, and stayed about a week each time. We spent time together not only in a physical way.
Eventually I asked if she had ever thought about something more serious. She said yes. We decided to become exclusive. The main issue was distance, but I told her I was open to moving in the future.
She suggested that I meet her mother, so I visited her city, met her family, and spent a week with her. It felt great. We talked openly about our relationship and I felt like we were moving into something more serious.
Then she went on vacation with her mother.
For the last two weeks, our communication has changed completely. We don’t talk every day — we talk every 3-4 days, mostly because I initiate. The conversations are very short and shallow. She rarely asks about me or shows curiosity about my life.
I understand she is on vacation and spending time with her mother, and I’m not expecting constant texting. However, I feel that a small sign of interest would be normal — even just checking in once during this time. She didn’t even let me know she arrived at her destination unless I asked.
What confuses me is the contrast. She posts sexy vacation photos on Instagram Stories, while the only things she has sent me are random photos like a bug on a tree. I’m not judging her for posting anything — it’s more about the fact that I feel excluded from her life while we are supposedly building something.
I genuinely care about her and I don’t want to throw away something that has meant a lot to me, but I also don’t have the energy for a situation where I feel like I have to ask for basic attention or where the effort feels one-sided.
If this was someone I had just met on Tinder, I probably wouldn’t go on another date after this kind of communication. The difficult part is that we have years of history and I don’t know if this is just a different communication style during vacation, or if it shows a bigger problem after moving from FWB into a real relationship.
Do you think this is something that can be fixed with a conversation, or is this a sign that I should let it go?