High Sierra Contacts Truncation Problem Workaround
I was unable to find an active question regarding the High Sierra contacts truncation problem so started a fresh thread for those who may be searching. The problem, as you know, is that data entered in the 'notes' section may be truncated and hidden from view on the Mac after the first few lines. One commonly mentioned workaround is to enter the notes section and hit a return, or backspace, whereupon the rest of your notes appear.
Another workaround I have not seen elsewhere is to use more carriage returns in your notes! If you use lots of short sentences and lots of carriage returns, then lots of data is visible. If however you keep your notes in a continuous paragraph, then you're lucky to see the first two or three lines. On notes with lots of one-sentence paragraphs, I can view over 30 lines of info without resorting to adding CRs or backspaces to see them.
Hope this helps. And Apple, please, get on the ball and fix this bug. We're now up to 10.13.3 and this is still not fixed.
See also:
High Sierra Contacts – Is the Notes Section Truncated? – MacMost
Mac mini, OS X Yosemite (10.10.2)