Im diagnosed with DID and i have had frequent intense Jamais vu as long as I can remember.
Usually it starts like this ominous feeling coming down from the sky, its the weirdest thing, then ill start to get super derealized.
It does seem to be a trigger thing, certain situations, smells. next time ill try to remind myself that its the feeling that is unfamiliar and i haven't actually entered another universe or something :3
(you have to be able to laugh at yourself or depression will get ya)

Dissociation comes in many forms. You have derealiztion, like they've been talking about which usually has to do with how you perceive the world around you. Depersonalization, like when you dont recognize yourself in a mirror, or you look at your arm and youre like "is that what a human arm is supposed to look like?" and it gets all distorted. people experience that in a myriad of ways, those are just my normal ones.
Then you have like, hard dissociation where you get "switching" as in DID. If youre having that youll probably have blank periods in your memory, or "time loss" where you find yourself in places and dont know how you got there, etc. People might say you did things you dont remember doing, like you already walked the dog ten minutes ago. memory gaps.
or the feeling of watching yourself but having no control of your body is a normal one for multiples, but not everyone who has these symptoms will have DID. it also has to do with how often it happens.
Most people will experience one or two dissociative experiences in their life.
"i dont remember how i got out of that car wreak, I just remember the fireman putting a blanket on me."
that sort of traumatic memory gap is relatively common.

There are many dissociative disorders, OSDD (formerly DDNOS) is similar to DID, but not exactly- then theres unspecified dissociative disorder.
I think a lot of the debate about the validity of DID comes from a general lack of understanding of how prevalent dissociation is... you know, its just not a part of our vocabulary. People dont even know how to talk about it.

Language creates culture. If we use terms like "dissociation", "derealiztion", "jamais vu" we can probably create an atmosphere where stigma of dissociative disorders is lessened. hopefully.

Anyways, DID is just a collection of certain dissociative traits. The best thing to do would probably be to read the DSM 5 descriptions and talk to your therapist about your concerns.
But more than that, to anyone who might read this who is having symptoms; find a space where you can talk about it. You're not alone, and isolation is hard.
My experience has improved a lot since i found other people with mental illnesses/disorders who understood what i was going through.

excellent article.
id love to see some research done on the prevalence of jamais vu in different groups & cultures.