Sometimes we all succumb to the thoughts of "am I faking?" especially when we see the disorder presenting so differently in someone else, as a caretaker I know it well with some members of my system.
So I thought we'd start off with the diagnostic criteria for DID that is in the DSM-5. This is the only must have with dissociative identity disorder.
Disruption of identity that is categorized by two or more distinct personality states.
Recurrent gaps in the recall of everyday events, important personal information, and/or traumatic events that are inconsistent with ordinary forgetfulness.
The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
The disturbance is not explained by cultural or religious practice.
The symptoms are not attributed to the physical effects of a substance (ie alcohol intoxication) or underlying medical condition (ie complex partial seizures)
All of that is pretty standard, you have alters, you have amnesia, and it negatively impacts your every day life and it's not the result of a spiritual practice or substance abuse. That is all the criteria that you need to meet for suspected DID to be DID.
I know that there's a lot of self proclaimed misinformation experts online who bring out a lot of anxiety regarding faking DID. But the truth is a difference in presentation beyond the criteria for DID is not indication of faking DID. It's important to note that DID is severely under researched and even articles in the last 10 years are outdated (such as core theory being disproven semi recently by the theory of structural dissociation).
If you're polyfragmantion, if you have subsystems, if you are introject heavy (fictive and/or factive) there is a reason for it and you are NOT faking for having difference in presentation. The reason all those misinformation blogs don't focus on those subjects is that the research regarding it is very lackluster as the current moment.
The brain is very intricate and your presentation likely could be influenced by commborid disorders that others you see online do not have. Personally we have OCPD and the presentation of OCPD commborid with DID is something we have yet to find any research papers on.
You know yourself better than strangers online. You know your symptoms and your trauma better than strangers online.