OMG! Never mind! I found it. The thread appears in My Activity list because one of the participants in that thread is in my Friends List. Bit weird, but ok 
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I use the My Activity view often(under Profile) to see if any threads i’ve been active in has updates.
I noticed a thread in the list, In Set timer by event node, Runtime Looping dosen't work - Blueprint Visual Scripting - Unreal Engine Forums where I never posted anything in but is in the My Activity list.
Is this a bug in the forum software? Is there a security issues? Am I missing something?
Its not a big thing, I was just wondering…