I don't know much about the subject specifically in Gaza or in Palestine in general, aside from this academic paper which is about the use of pinkwashing as a colonizer tactic. Regarding advocacy groups it mentions the group alQaws. Here is an article by alQaws: Queer Liberation & Palestine. Quote from article in which they warn about the weaponization of LGBTQ issues to further colonial agendas:

Israeli settler colonialism, and tactics such as “pinkwashing” weaponize our queer experiences to place us in opposition to our own society and communities. Pinkwashing is a form of colonial violence. It promotes harmful narratives and policies that alienate queer Palestinians from our own communities. Our answer to pinkwashing is to say that liberation is indivisible, and that there will be a place for all of us at the rendezvous of victory. The Israeli criminal government and Zionist LGBTQ movement manipulate and exploit queer Palestinians’ lived realities to advance a colonial agenda. The standards for solidarity and action cannot be set by the colonizer.

Another article from them: No Queer “Co-Resistance” with Colonizers: Confronting Normalization and Pinkwashing

In alliance with anti-colonial coalitions, alQaws developed and popularized the concept of “pinkwashing” to expose how Israel and its defenders use the language of LGBTQ rights to distract from the oppression of Palestinians. Over the years, Palestinian activists came to recognize that pinkwashing is not simply an outward-facing propaganda machine—it is a direct form of colonial violence, one that pushes Palestinians to view ourselves and our communities through the lens of colonial prejudice.

Pinkwashing relies on exploiting progressive rhetoric about “tolerance” and “gay rights,” to conceal the violent nature of the occupation and settler-colonialism in Palestine. Normalization, similarly, draws on liberal ideals of “dialogue” and “partnership.”

5 Way to Support Palestinian Queers

Perpetuating tiresome tropes of presenting Palestinians as inherently oppressive and Israel as a liberal state that protects LGBTQ rights is counter-productive and factually baseless. Israel is a settler-colonial state that offers no rights to Palestinians, queer or otherwise. Our struggle as queer Palestinians is against Israeli colonialism as much as it is against homophobia and patriarchy in Palestine. Israel uses pinkwashing tactics to lie about “saving” LGBTQ Palestinians from their society. We ask that you steer away from these lies that are intentionally used to justify their colonization of Palestine. alQaws and our allies in Palestine will continue to amplify our message as well as provide protection and a political home for LGBTQ Palestinians. Israeli LGBTQ groups do not have a say in the work that should be done to fight patriarchy and homophobia in Palestine, including the incitements led by the Palestinian police.

As I said, I don't know much about it beyond the above, which I have not looked deeply into, so take this information with a grain of salt.

As far as I’m aware they still follow the British criminal code where it was illegal.

There is an advocacy group, so it’s not totally an ignored subject but probably a fairly low priority.