I don't know if this is new or not but:
"A diagnosis of gender dysphoria in childhood is rare.
Most children who seem confused about their gender identity when young will not continue to feel the same way beyond puberty. Role playing is not unusual in young children."
www.nhs.uk/conditions/gender-dysphoria/symptoms/
And:
"It's not unusual for children to show an interest in clothes or toys that society tells us are more often associated with the opposite gender.
With toy stores dedicating whole floors to colour-coded boys' or girls' toys, as just one example, it's not surprising that parents may expect a child to closely match traditional expectations of how male and female genders should behave.
You may be worrying that your child's exploration of different gender preferences and behaviours is not "normal" or you may feel that such explorations are somehow your "fault". However, none of this is the case.
We now believe that gender identity is on a spectrum, with male at one end, female at the other and a "diversity" of gender identities in between. These can include male and female, non-binary or even agender (no gender).
A young child's exploration of different gender identities is quite common and, in most cases, will fade. However, in some, it will continue into later childhood and adolescence."
And:
"In many cases, gender-variant behaviour or feelings disappear as children get older – often as they reach puberty. Many will go on to identify as gay or lesbian."
www.nhs.uk/live-well/healthy-body/think-your-child-might-be-trans-or-non-binary/