Kid's mom keeping me from birthday party
TLDR: kid's mom said I could come to upcoming birthday celebration, then reneged, saying "my behavior needs to change." (I'm not the problem one)
Hard to even know where to start...
Potentially relevant details:
-50/50 custody with week on/week off parenting schedules.
-I have a pregnant girlfriend that I'm later moving in with. (Disclose this to my daughter's mother early on)
-We seemed to begin having issues with what feels like retaliation after I filled a temporary motion to restrict parenting time (having my daughter stay with me exclusively until the situation was remedied) after her mother disclosed that her home had become infected with bed bugs. This also coincided with her moving them in with her then boyfriend without telling me. (I only learned of that fact when I went to pick my daughter up right after learning about the bed bugs).
-We have been split for about 4 years, she decided after we broke up to relocate 4 hours away from where we were living so that she could save money by living with family. I was lucky enough to be in a position to be able to relocate, and uprooted my life and made the move so that I could stay in my daughter's life.
My daughter's mom is a rather high conflict individual (exhibits manipulative narcissism which constantly gets projected onto me) that recently started making comments in family court proceedings about feeling unsafe around me and wanting to limit her exposure to me. She requested communications happen through Taking Parents in court and the judge has compelled me to both pay for this service as well as exclusively use it to talk to my ex. On top of this, she's blocked me on social media, and had her new husband (whom she moved in with, became engaged to, and later married [3 months after engagement] without my knowledge, and has gone as far as to conscript others into keeping the secret as well) as well as her father also block me. Slowly I have been more and more ostracized from the new life she enjoys without me in it.
Recently, I reached out to her to open up lines of communication regarding our daughter's upcoming birthday (9 days in advance) as we have done joint birthdays with her ever since we split. I was expecting we would continue that again this year. I asked if we could schedule a phone call to discuss plans, what/how I could contribute, etc.
During the phone call she mentioned that she was planning a party for the day before her actual birthday so certain guests would be able to attend, and that it would be fine for me to join in.
I mentioned I'd reach out via TP a little later after I'd had a chance to talk to my girlfriend about it, and within a couple hours wrote "We would love to participate at noon on Friday."
Today, she responds, "Hey, I have been thinking about it and talking it over and decided that it’s best if we do separate things this year for [daughter's] birthday. Maybe down the line after a new pattern of behavior on your part has been established, I’ll be able to trust that we can interact in a way that is comfortable and healthy for everyone but right now that is not the case. You are entitled to have [daughters name] during her birthday from 2 PM until 8 PM on the 11th as stipulated in our parenting plan."
I'm really at a loss for how to respond, or if I should at all.
Any advice from those that have dealt with stuff like this? Knowing that these communications can be submitted to the court in the future, I want to be careful with how I word things, but also want to stand up for myself in this situation, and do what I can to dispel any suggestions that "my behavior is an issue."
My girlfriend believes that this may be an attempt to both assassinate my credibility and character in the future, as well as some form of a trap to get me to act or react in a way that she can twist towards her narrative, like she's trying to build a case against me or something.
Thanks in advance.