Pinning and unpinning of topics is at the user level, but only for topics pinned by us ‘leaders’ or ‘staff’. This means the user is free to make changes to pin/unpin these as they please.
Note: Pinned topics take up important real estate for active topics that follow. So we do try to keep these to a minimum.
There is however also a setting ‘enabled by default’ to unpin any topic once you reach the bottom. This may cause some confusion and may result in topics, we ‘leaders’ have set to be pinned, to get unpinned again. There is no way for us to make a distinction, each pin is treated equally, unless this behaviour is disabled forum wide.
Thankfully you can change this unpinning behaviour yourself through your ‘Profile Settings’.
Visit your profile page through your user icon at the top right
Now select the ‘Interface’ settings and look for the option to:
‘Automatically unpin topics when I reach the bottom’ and remove the check mark if you prefer to keep pinned topics pinned.
I am sure some will find this useful, while still allowing you to pin/unpin any topic pinned by us as you seem fit.
Suggestion: You can ‘bookmark’ topics you find important to get back.