mross

Under 'All Activity', 'My activity Streams', select the steam you want to be 'default' and make sure the green tick is showing as on the top line here

 

Try deleting cookies, it might be corrupted and synchronising from one to the other machine.  My phone and laptop are behaving at present.

Click on your own profile, top left and then 'sign out'!  Simples.

Click on the drop-down top right by your name, Account settings, signature - delete image file and save

You must create a custom stream.
On the home page go to 'MyActivity Streams'
Select 'Create New Stream'
Where it says 'Stream Title write VNC or whatever you prefer - I added my initials so that I know this 'stream' is something I created and can edit
Under 'Show me' select 'Content items, Comments and Reviews'
Under 'Read Status' select 'Content I haven't read'
Under 'Following' select 'Everything'
Under 'Content Types' select 'Topics'
Under 'Ownership'select 'Everything'
Under 'Time Period' select 'Any time'
Then click on 'Save Changes'
Go back to 'My Activity Streams' and select the stream you have just created
To the right of your new streams title are three, greyed out icons.  Click on the 'tick' to make this stream your default.