How would you handle this situation?

Christy • 34 Married to my best friend ttc #1 together
Not real sure which section to add this in so i put it here. very long.....sorry....How would you handle this situation? Dh and I have been best friends for over 15 years, been together since 2011, and married since 2013. He has a son and a daughter from his first marriage. I have been around these kids and their mother since before they were born. SS is in the 6th grade and SD is in the 3rd grade. SS was diagnosed with ADD/ADHD in the 3rd grade, and also has dyslexic tendencies but not a diagnosis and needed speech therapy when younger. SD has had speech therapy, been behind in reading every year, had dyslexic tendencies also. I picked up on these tendencies when she was is kindergarten and have worked with her when she's here and worked with her teachers, had conferences with them etc so that we are on the same page with what and how to approach her education issues since kindergarten. Played a very active role in her and SS education since 2012. This year, SD transitioned from the elementary school up to the intermediate school. SS has been at the intermediate school since 3rd grade. Last year I spoke with the counselor about some issues SS was having with his homework and learning. She advised me that I was able to do what I've been doing as far as making sure the teachers and I were on the same page but was not able to make decisions such as 504 accommodations etc. Which is fine....that's a decision dh and his ex wife need to make. Although the ex wife refuses to.... well.... this year, the ex wife scheduled and went to parent teacher conferences with SD's teachers.....great... but she doesn't let dh know ahead of time or relay the context of the conferences. Since dh works late every day and I have always met with the teachers, SD wanted me to schedule a conference with her teachers. Great. I called to schedule a conference. The day I was supposed to meet with the teachers, I was informed that they could not talk to me about the kids' education. ...and that I was not allowed to sign them out of school either (which I've also done since 2012. Last Friday SD's teacher handed me a permission form for dyslexia testing for dh to fill out and sign..(they had already sent one to ex wife and she never returned it)... so, I brought it to him, he discussed it with ex wife and he gave permission. Yesterday when i picked them up, the teacher handed me a permission slip for after school tutoring on Wednesdays. I let her know that dh was probably not going to sign it due to its a 60mile round trip to pick them up from school and SS would still need to be picked up at regular time. So...we discussed it and came up with a plan that I was going to discuss with the teacher this morning. I get to the school and not only would they not discuss it with me, they barely let me turn the form in for him. They said they need a signed letter from dh AND ex wife saying they can talk to me... I know he brought it up to her when it was first mentioned but I never asked what she said...I assume she didn't like the idea since it hasn't been done. So.....my question is....what do I do. Dh had already told them they could talk with me but that's no good. We can't afford for him to take off work every time something needs to be discussed with the teachers....