It looks like there is a bug in TAdvMemo and the squiggly lines that should indicate a misspelling does not automatically show up during typing when WordWrap is not set to wwNone.
We are using TMS Component pack v8.3.4.0 :update Sep 23, 2016.
A sample project can be downloaded from https://ufile.io/2g3og
Is this a known bug? Is there a fix for it in a later version?