"Name an issue that transmascs faced not faced by other trans people".
That's the thing though... I don't believe there are any issues faced by one group of trans people that are never faced by another group trans people (or even some non-trans ppl!)
There are issues that are more commonly faced by certain groups. I.e. transmascs are more likely to deal with transphobic discrimination during pregnancy. But that's not exclusive to us, some nonbinary people and intersex transfems who can get pregnant may face the same issues.
Transfems are more commonly treated as predatory and dangerous, but that's not exclusive to them either. Other trans people are demonized and get treated as dangerous simply for existing as well.
This is why we talk about the ways these oppressions overlap. People are constantly asking us to prove our oppression is completely unique in some way, but our point is that it's not! Neither is yours, I'm sorry to say. Other people face similar issues that you do. Which sucks that we're all going through it, but it's wonderful that we can be here together as a community to support each other.
There's a lot of separatist fear mongering that tells certain groups of trans people "the other group can't possibly understand your oppression, so you can't trust them, they are unsafe" which is incredibly dangerous rhetoric. When we acknowledge the way our oppression overlap, we realize we can find solidarity and safety nets together. Telling someone that other trans people will never understand their struggles is not only demonstrably false, but keeps them isolated.
We can talk about how these forms of oppression manifest without talking over each other, by inviting others to share how their experiences overlap. That is literally all I want. I love when I talk about transandrophobia and a transfem talks about how her experiences with transmisogyny overlap, or a nonbonary person talks about exorsexism or an intersex person talks about intersexism.
We can learn so much together by recognizing how these oppressions intertwine and fighting against them together.