I can't seem to connect my cratons together to move them

So…I just started using GPlates about a week or so ago. Like I’m sure a few of are, I’ve been following Artifexian’s tutorial and though helpful thus far, I can’t seem to get over this one hurdle. I have 12 cratons and they are currently on one supercontinent. I’m trying to break up said supercontinent so I have three groups. Two groups of three and a group of six. The group of six and one of the groups of three are working fine and I can move them and everything. However, one of the groups refuses to work. I have copied my rotation file and the group that refuses to move has Plates 100, 500, and 900. I’ve tried various combination of plates following others, it appears that it’s with Plate ID 100.

100 0.0 90.0 0.0 0.0 000 !
100 850.0 90.0 0.0 0.0 000 !
200 0.0 90.0 0.0 0.0 000 !
200 850.0 90.0 0.0 0.0 000 !
300 0.0 90.0 0.0 0.0 000 !
300 850.0 90.0 0.0 0.0 000 !
400 0.0 90.0 0.0 0.0 300 !
400 850.0 90.0 0.0 0.0 300 !
500 0.0 90.0 0.0 0.0 100 !
500 850.0 90.0 0.0 0.0 100 !
600 0.0 90.0 0.0 0.0 200 !
600 850.0 90.0 0.0 0.0 200 !
700 0.0 90.0 0.0 0.0 300 !
700 850.0 90.0 0.0 0.0 300 !
800 0.0 90.0 0.0 0.0 300 !
800 850.0 90.0 0.0 0.0 300 !
900 0.0 90.0 0.0 0.0 100 !
900 850.0 90.0 0.0 0.0 100 !
1000 0.0 90.0 0.0 0.0 200 !
1000 850.0 90.0 0.0 0.0 200 !
1100 0.0 90.0 0.0 0.0 300 !
1100 850.0 90.0 0.0 0.0 300 !
1200 0.0 90.0 0.0 0.0 300 !
1200 850.0 90.0 0.0 0.0 300 !