Incredible in person but distant over text.

I’ve been talking to this girl for a little while now. We would text here and there, and finally made plans to meet up when everything opened up. The dates we have are amazing in every way, and when we see each other she always seems to be interested in me. But one major red flag is her texting. I always get left on read. And up until recently, I chalked it up as the conversation ending abruptly. Each message that resulted in me being left on read was one that could be justified as an end of convo message. However, my most recent text asking if she was free was left on read. A HUGE red flag for me. It’s very confusing, as she invited me out the previous week, but I couldn’t because of schedules. Now I ask her when she is free so we could meet up, and I get no response. I’ve been told that interested people will show that they are interested. She shows it when we are in person, but is cold over text. What might be going on in her end? And should I just move forward?