No need to make unique macros
In fact, the macro's used to change focus are the same on all my accounts/characters.
It can become a huge macro this way, Macaroon ftw \o/

Code:
/run UIErrorsFrame:Hide(); 
/cleartarget
/focus [exists]Osaar;[exists]Malekyth
/follow focus
/run UIErrorsFrame:Clear(); 
/run UIErrorsFrame:Show();
Is what will fix your problem probably, i'm not sure if it was exist or exists, my highest bid is on the latter.
Mine kept messing up untill I used the exists even pre patch.

I'm not sure why you had the follow with names tho, you just set the focus so why not just follow that