Hi,
I’m using an boolean array with a size of 45 and also 3 single byte values in my struct without any problems. But I’m using the normal (not I2C) Variant.

Maybe you shoud try to bring your boolean data in an array?
Also you can try to change the baudrate up/down. My best experience is at 9600Bauds
Don’t forget the grounding of all parts. Maybe start at first with only two Arduinos and let it grow when it works

Greetings
Pac-Man