Well, I decided to keep this ticket as is and open a new ticket for the aforementioned issue (carved pumpkin overlay on F1), hoping it won't be closed at the beginning.
@MrMuskle Bro, I just opened this ticket to suggest carved pumpkin overlay shouldn’t hide when on F1, all other content was additional and offered as a cover for that suggest, and simply you've cleared the main point of the ticket by removing that suggest. (actually, I had already seen the ticket regarding the carved pumpkin overlay, and since I didn't accept the answer given to it and couldn't open another ticket on the same subject, I opened the current ticket with a few more things added.) (However, I think it's really a bug that the carved pumpkin overlay is hidden when using F1.)
I don't really think that Ghasts should be leashable. currently, only a few mobs (and a very small number of neutral and hostile mobs) can be leashed.
https://minecraft.wiki/w/Lead#Leashing_mobs
Still affects 25w19a. Given the centrality of having a Ghast in the new update, it's a good time to fix it.