Depersonalization with anxiety around switching

We are an experienced system with a large amount of alters. Normally, switches happen without too much difficulty, and feel complete. But recently, we have been struggling to feel anyone concretely at the front, and trying to initiate a full switch or feel like a solid person is causing a lot of anxiety. This has been going on for a few days, and is getting pretty distressing. We have a partner system, and the partner of the current frontier over there wants to front and be with him, got close enough co-con that we felt she would be able to complete the switch, but wasn’t able to anchor herself. Does anyone have experience with these sort of episodes? Does anyone know what causes them, how long they typically last, and what can help us feel normal again?