Sometimes when this happens it means a person has healed enough that its no longer triggering when a therapist is gone...

example when my therapists was on vacation I used to get so worked up about them being unavailable should something happen, that I would end up triggered, which caused me to dissociate (feel numb, spaced out, disconnected ) and an alter would take over to handle that. but over time I learned what I needed to take care of myself (grounding, breathing, not letting my negative thoughts send me into panic/anxiety attacks because my therapists were not available) because I was no longer triggered by my therapists not being available I no longer dissociated (felt numb, spaced out disconnected) which meant my alters did not take over to handle this situation any more.

maybe something similar is happening to you. you may have healed to the point where your alters know they do not have to take over during the times when your treatment providers are not available.