Hmmm.

Sorry. :-)

I do this sometimes when in a conversational tone say on Slack or IRC to show I'm actually thinking/confused by the direction the conversation has taken. I think this is better than the person I'm interacting with thinking I've just bailed.

This is not the same as, uhhh, me, uhhh, like, uhhhh, putting filler words into, uhhh, my writing.

It is used to enhance the communication by making it more representative of a good conversation, as opposed to using filler words.