I asked her the next day :
What happened yesterday, I am letting last night go but would like an explanation
no reply via WhatsApp, and only 1 tick, she's blocked me
This message can potentially be perceived as confrontational, even threatening: she might be thinking, "he's
letting last night go, but what would happen if he gets wound up by something else I do wrong / mess up on? Will I be safe?" and so blocked you so she can be on her safe side.
We have no idea why she's ghosted you, maybe she's had some issue or emergency, maybe she got alarmed by your message, maybe she's just too busy or unprofessional. Whatever the reason you just need to take it as it is and move on as:
she's under no obligation to meet you any more than you are obligated to meet her,
nor does she owe you an explanation (as courteous and professional that would be), not even with having promised to see you the first time the booking failed.
If you're still concerned, curious or find yourself in this situation again, try sending
Hope everything is ok? Didn't hear back from you for our arranged time? and just leave it at that for the person to respond.