Eighth note tie bug

While working on a piece in 3/4 time, whenever I had a measure ending in a half note tied into a dotted half note, a mysterious eighth note would tie itself to the tied dotted half note. I had been copying and pasting this particular segment when this occurred. It is quite frustrating as whenever I play the line with the bug alone, it plays the extra eighth note. If I delete the eighth note, then it stays as an eighth note rest. When I delete the measures including the mysterious eighth note and the immediate measures around it, the eighth note rest replaces the whole rest in the measure after the measures I had deleted.