God, this resonates with me.
Stbxh does it too. With the added bonus that my eldest had ASD and ,earning difficulties, and associated anxiety.
So stbxh ramps it all up nicely, on the pretext of 'just saying goodbye' (so bloody say it then, and go, don't make such a meal of it), and I'm left picking up the pieces. Similarly, he works late, often not getting home In time for the dc's bedtime, so will phone to say goodnight. It he gives a window, between 6 and 7pm when he will phone. Which just means that come 6pm, eldest is clock watching, fretting over when daddy will call, what time, he said he would, will he be late, what if he doesn't call, etc. Potentially for up to an hour, by which time she is an absolute basket case, no one can get a word in edgeways, people get hurt (can't handle her emotions, and eats frustrated/lashes out). All because he can't just behave like a reasonable adult.
Or he makes a big deal on the rare mornings he is here when they are getting ready for school - will come in as they are getting dressed, to say goodbye so he doesn't forget (he's not dressed, so clearly not leaving), then will say goodbye again 'in case you're dashing off to an early club' (he should know their timetable!), then again usually while e cleaning teeth. He did all this this morning, then by the time we were coming down to breakfast, he was still faffing around in the kitchen not having left yet, which made dd1 explode into a round d of 'why haven't you gone, you said you were going, are you late?' and so on.
I long for some peace and stability, because all this emotional upheaval over just leaving for work is ludicrous.