I finished writing a report for a course (in my undergrad) and I submitted it to Turnitin for a similarity check (8%) and in one part I noticed it highlighted fragments of one sentence.
The flagged sentence has about 8 words in a row in a 26-word sentence that matches another report but the sentence itself is different than the one Turnitin says it is similar to.
I did paraphrase this sentence from a completely different source with appropriate in-text citation and bibliography and ensured I wasn't using any direct quotes from that source. That being said, I am concerned that because the technical wording is so similar to what Turnitin picked up (those 8 words in a row that are the same) it might be cause for concern.
Sorry, I don't know if I'm being paranoid or if I should legitimately be worried.