Hi Rick,
the reason for such behavior standard code template for C++ with key "///" which expands to long "////.....". I am sure, when you pasted comments, you have seen tooltip proposing this template, and with pressing Enter you have accepted it, and editor has inserted it. Engine checks text from current position back, after altering text, and if text ending matches to any template key suggest it.
Generally this is often problem with templates, if you typed something in the end of line. I have not found elegant solution for solving of this, but there are tow workarounds: one is to
remove Enter from tool tip accept keys and another one is just dismiss code hint suggestion with Esc or by waiting for a some time.
BR, Alex.