Your inventory tabs are the thing that usually surprises most people the first time. On your first character in your first/standard league, let's say you have 10 inventory stash tabs (you purchased a few extra), and they're probably very close to full.
Then you start the next league. That character (call it League 2) also now has 10 empty inventory tabs. You play the league and fill them up. The league ends.
Your League 2 character is now moved into the standard league server. When you open up your inventory in there now, both characters have access to the full inventory, all 20 tabs. BUT since you've only purchased 10 tabs, all of the "newest" 10 tabs are there, but they are in remove only status.
This, I understand. It makes sense. But the issue is when I go purchase a new set of 3 stash tabs. If I play in the new league I now have 13 empty tabs to use. As expected, Cool! But when I switch back to my standard league characters, I don't have 3 new empty tabs. It selects 3 seemingly random (if there's a logic someone please explain it, it's not highest on the list) tabs from my "Remove Only" group and removed the Remove Only lock. So I don't have any more 'new empty' space, unless I simply sell or drop the items I'd saved in those tabs. Frustrating. After playing league after league, I have a huge list of remove only tabs...and unless I want to spend hundreds of dollars on new tabs, I'll never get any new empty tabs...meaning I have to just throw away crafting components, unique items I've saved, etc.
And yes, I own multiples of every tab type out there, so each season I get multiple remove only versions of those same tabs imported. The least they could do would put a "merge" button onto each of the specialty tabs. So I don't have to spend hours/days moving items from a remove only tab. As an example I have multiple "Unique Collection" stash tabs. Merging these is a royal pain. Same goes for Map tabs, Essence Tabs, Ritual Tabs, etc.
Frustrating. But at a base economics level, I understand that this is the way that many of these, especially a 'free to play' company makes its money.
Either way, GGG, I've got *thousands* of hours over the last 14 years playing POE/POE2. I love the game. Thank you GGG!