Cis-genderless or Cisgenderless is defaulting to assigned sex/gender due to lack of gendered feeling and possibly lack of understanding of gender. It is similar to agender, but when asked, a cis-genderless person will give their assigned sex/gender. For example, an AMAB cis man may feel perfectly fine with identifying as male, yet does not feel any sense or feeling of being so. Cis-genderless is not inherently LGBT+, but rather a term to define the feeling or sense of gender a cisgender person may lack.
History
The cis-genderless flag was created by AVEN user ixi on August 27, 2015. The white stripe represents genderlessness, the pink stripe represents cis women, blue represents cis males, and purple represents cis intersex people.
References
https://heterogen.wordpress.com/2020/01/06/growing-up-cis-genderless-without-a-word/
https://heterogen.wordpress.com/2020/01/05/on-the-term-cis-genderless/
https://www.asexuality.org/en/topic/86589-2-cis-group-cis-cis-and-cis-genderless/
https://www.asexuality.org/en/topic/124514-proposal-for-cis-genderless-pride-flag/