They are two completely different communities that just happen to share their names. (And one of them is full of tankies, while yours isn't)

How this works is the same with email: You can have john.smith@gmail.zz and you can have john.smith@outlook.com , but although those do have the same first name, the two addresses do not point to the same mailbox.

If a community is on your own instance (servers are called instances on Lemmy), then the part after @ is not shown. So, there is asklemmy@lemmy.world, and there is asklemmy@lemmy.ml. The latter one is luckily empty, as nothing on .ml is written without serious brainrot.

The one you see only as "asklemmy" is asklemmy@lemmy.world. There are actually this many asklemmys:

Each of the above is an independent community. Each one was founded by a different person and has different moderators, etc.

When you login to Lemmy, you go to lemmy.world and login there. I don't. I do not have a user account on lemmy.world, which is one of the instances (servers) for Lemmy. However, I do have a user account on sopuli.xyz, which is another instance. When I log in to that, I can read anything written on any instances that have federated with sopuli.xyz. We are having this conversation in a community on yet another instance:
As you can see there, this community is located on an instance called lemmy.uk.

So, I am reading this through sopuli.xyz, which has a connection to lemmy.uk. When I write something, Sopuli sends all the text to lemmy.uk which then saves it. And then your instance, lemmy.world, has a connection to lemmy.uk as well, and shows you whatever is shown on that instance. When a Lemmy-instance creates such a connection to another instance, it is called federating.

The nice thing about this construction is that if someone tries taking over Lemmy, they only take over their own instance. Its users can just migrate to another instance, create an account there and continue almost as if nothing had happened. And if some instance is not moderating its users' activities properly, other instances can defederate from it. That means: They can stop showing their users content from the badly behaving instance, and also the users from that instance won't see anything held on the other instance.

I hope this blabbering helped!

Tbf, PieFed's categories of communities and user-customizeable and shareable Feeds greatly simplify the UX in working with communities (ironically more so on a mobile than desktop, surely an oversight that will be fixed soon).

I do have a subscribed category both in Sync for Lemmy, and the website.

On Voyager there is Home which is subscribed communities. All / Home / Local.