Parents: help me parenting while separated (2)

[Ripe]

We did not have the meeting yesterday.
STBXW was supposed to show up at my place after the kids would be asleep, that is, around 21h30.
I waited and waited. I decided to not call her.
At 22h25 she called. She told me she was not feeling well. She did not apologize for the late call. In the back I could hear her best friend, the divorced one, talking and laughing.
Why the lie?
We rescheduled the meeting for today, again after the kids are in bed.

Today S9 had a school show. I managed to leave work earlier and surprised him. He was thrilled when he saw me. STBXW was also there. We sat in opposite sides of the classroom. After the show STBXW tried to postpone the meeting. She clearly showed her annoyance to have the meeting at my place (our former home). She suggested to have it at a coffee shop. I replied it was a totally inappropriate place. The meeting was confirmed for tonight at my place.

Just 10 minutes ago STBXW called. She said that having the meeting at night was not good because both of us are usually tired by the end of the day. She suggested an afternoon of the weekend. She said we could have some babysitter taking care of the kids while we would talk. I said no, since this is my last weekend with the kids before they fly home for Christmas without me. STBXW became irritated. She said I always scheduled these meetings for when I am in the capital (I work in another town and sleep there on the days I don't have the kids with me). I did not understand the argument - am I supposed to drive 50km after work just to meet her when yesterday and today I am staying at the capital and don't need to drive the 50km on purpose just for a meeting?
She ended up accepting to come tonight.
I politely thanked her.
She ended the phone call by saying: "I am glad that you thank me, because there are a lot of thinks you don't thank me for".
I didn't see this coming and did not understand it.
I wrote some days ago that STBXW was clearly melting down and becoming as of late much nicer when talking over the phone and face to face. I don't know what happened.