The phone being off is a boundary issue (a control issue for her).
Let her know you would prefer that she keeps her phone on while she has the kids, as their father you need to have the ability to get in touch with them when needed. Document it. Put it in a e-mail after the conversation.
M22,H45,W45 S21/18D12 Retain faith that you will prevail in the end, regardless of the difficulties and at the same time confront the most brutal facts of your current reality, whatever they might be.
