Make sure your send your letter of parent concerns (including the behavior/FBA situation, anxiety challenges) in advance of the upcoming meeting.
Did the school state in the PWN why they felt they didn't need to conduct an FBA? Did the PWN state that the people who attended that meeting initially approved the request for the FBA, but the district later stated those individuals didn't have the authority to make that decision? Who represented the LEA in the meeting in which the FBA request was denied?
If the teacher previously agreed to providing a more detailed communication log, but now says it's unnecessary, perhaps she's getting pushback from administration? Have you talked with the principal or a special education case manager?
Have you had multiple IEP meetings regarding this? If so, it sounds like it's time to consider your procedural safeguard options. Have you considered mediation? Due process is another option, but review https://adayinourshoes.com/iep-due-process/ on that.
Do you have an advocate? There are Parent Training and Information Centers (PTIs) in each state (https://www.parentcenterhub.org/find-your-center/). You may want to reach out to yours if you haven't already to see what assistance they could provide. Maybe they would attend mediation with you?
Jenna's post in IEP Meeting soon want to feel prepared. was marked as the answer