X-Post: please help me [35F] explain to my husband [34M] these triggers

First, a little backstory:

I was married to a guy for about five years. We divorced about nine years ago. A year before we started the process, I discovered he cheated on me. The way I found out was he was being very protective of his phone. He had taken a phone call outside and quickly hung up when I walked up to him. I managed to get his phone and saw the text messages. He obviously didn't get any better and continues to cheat on girls to this day. I know bc he dates some of my acquaintances occasionally.

Forward to now. I have been remarried to a guy that has been a close friend since high school. We celebrated our fourth wedding anniversary a few months ago. We have a toddler.

For the past couple years, he has started doing the same thing. He is very protective of his phone and will even go out of his way to take phone calls out of earshot. I have explained to him many times that those are triggers, and he doesn't seem to care. He even goes out of his way to hide his passcode. He did so this morning.

Now, I really have no desire to go through his phone, but now that he's being shady about it I am hyper aware. It's eating me alive inside, and I just want to give up.

We have gone through marriage counseling, and it helped for a little bit. There are other problems in our relationship, but this one remains a regular thing. I don't want to go through another divorce, but I also want to be happy.

Please, Reddit, help me explain to him why his actions are causing the red flags. I've tried many times before, and he just accuses me of treating him like my ex.

TL;DR: My now husband of 4 years is doing things that trigger me to think he's cheating on me. Please help me explain to him in a different way.