Written Up After Calling Out With Fmla

Hey all, yesterday I called out of work for medical reasons, I got FMLA papers that day and submitted it with my HR (it is intermittent FMLA) I chose to use yesterday as the date for my FMLA since I get a few days a month. Today I got written up from my boss and he cited that my call out yesterday was a reason for it. My attendance prior was not great for medical reasons and at the time I had not had a FMLA. I got a verbal warning for those occasions but no write up. So I called out yesterday and spoke with HR about using my FMLA so I would not get penalized, HR said yes we can do that, I asked what i should tell my boss (it wasnt approved at the time, it was pending) they said i dont need to tell him anything so I didnt until later that day when I notified him of FMLA through text message because I had to per HR. Today during the write up I once again stated that yesterday was with FMLA and I have submitted that day through my work portal to be used. He still used it as a reason for write up.

Prior to the write up, I got a verbal warning several weeks ago and did not miss any other days or have any issues attendance wise. Yesterday I called out with FMLA, with HR, and they told me twice since I opened a leave with it he cannot penalize me- but then the day after all of that which is today, he writes me up. All communications were through phone, I believe the company records the calls based on the 'your call may be recorded', the write up was in a break room away from cameras and only one other person was with them, and its illegal to record without permission. (How can I document these conversations legally??)

Isn't this retaliation? Is this legal? I know im being very wordy, any and all advice would be appreciated. Thank you!

Location: Florida