Communicating with stbx in between mediation?

[Spotify]

We've been separated 3 years. 3 children with me. At second stage mediation (I initiated it) where we have an appointment for both of us coming up. I have seen my solicitor once with upcoming further appointment but not yet done decree nisi.
MIAMS was done separately and I was told yesterday he'd agreed to another appointment for both of us.
Haven't talked for several weeks and he's ignored children's facetime. Offered to take them down but a few weeks ago he said he'd come and get them in half term (about 6 weeks from when he said this).
I'm used to this behaviour which happened throughout the marriage. He goes on silent stints (days/weeks) and suddenly reappears as if nothing happened. He did not reply to my last two texts (about 3/4 weeks ago) so I've not tried to start any new communication up.
Should I be trying to find an 'amicable' way to communicate before mediation together (which I'm obviously dreading) or just leave it to the meeting and solicitor?

[noego]

You've tried communicating. He's ignored you. I'd leave it until the meeting or with the solicitor. Take screenshots of the texts just in case you need evidence.

[Spotify]

Thanks noego, I can't do any more really. I was going to mention about what I was going to propose in mediation, so he wasn't worrying too much but it's probably not a good idea.