It may happen if the current target segment has been already translated (or pretranslated in another tool). Then, CT does not remove the current (pre)translation. Note that pretranslation may contain invisible characters. You may create a ticket attaching the source file and indicating the segment which blocks the automatic insertion from the translation memory. I will try to confirm it for this segment. Also, please make sure you are using the latest version of CafeTran Espresso 2018 Akua,
I noticed some 100+% matches do not propagate. In such cases Ctrl + 1 doesn't work either. You have to click it with a mouse to have it copied in the target segment.