sometimes it also happen on the website (at least for me) so I don't think it's some jerboa bug, also note that this app is not even in beta at the moment, just give it some time.
I have found that for me it is only lemmy.ml communities. When I was on lemmy.ml it always happened. I moved to lemmy.world and now it is only lemmy.ml communities that do it. Desktop or mobile. It's an instance problem, not a jerboa problem from what I can tell.
This happens to me on lemmy.world as well, not using the app, curious that your move fixed it though. I think it might be a general lemmy issue rather than instance specific
Yeah this is why I'm asking because I've noticed it happens across multiple different instances. If it's a known issue then eh whatever I hope they fix it but it's still quite annoying.
I could be wrong but I think the first click works, there's just no loading indicator, so then you click a second time because it's unclear if anything is happening, and then shortly afterwards the successful response from the first click comes back and it just looks like the second click did something.
The simplest standard fix is to just immediately start a loading spinner that disables the button until the first request comes back or times out, then at least the user knows that something is happening. Some sites use optimistic updating though where they just assume the request will be successful, benefit being that the change happens as soon as the user clicks the button but the downside is that it may change later if the request happens to error out for some reason.
I have some that are also indefinitely pending. In my case, they seem to be on servers that aren't federated with the server my account is on. All communities on Beehaw.org are doing this. I am still able to post on them, but I'm not sure if they are showing on my front age or not.
I think it does send the request the first time you click, but it takes a while to get a response from another server. Try it with some communities that are local to your server and you'll notice it's not so much an issue. I'm not a Dev and not am authority on the topic, but I think it puts your request into a queue, this helps make sure that your request makes it to the requested server in the case that one of those servers is temporarily down for maintenance or updates.
What I think needs to happen is just to provide a visual response to indicate that your request is sent and awaiting a response, which doesn't usually happen until you click it a second time.
I assumed it was an intentional function on mobile. Kind of like "Are you sure?" without the pop-up. I've had to press twice for every feed I subscribed to so far, regardless of where it's hosted.