Why has she blocked me?

My boyfriend started a new job after few months he kept taking about this woman he works with saying she was helping him fill in job applications to get a permanent role (even gave her his loggin details) then she started messaging
He would delete the messages of her. New year's eve she messages saying happy new year 😘X I was stood at the side of him so I seen it he replied and when she replied to that he delete her last message
I found her last name through his emails I searched her through Facebook and couldn't find her then searched her on a friend's Facebook and there she was right at the top
Tried on mine again and she's no where to be seen why? ITS LIKE she's BLOCKED ME
Do you think there is something going on
Why has she blocked me?
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