Sorry I'm late - Bad new Find and Replace; can't drag files in. is now archived but I wanted to show you what I meant: I was complaining about the new Find and Replace.
It seems to get confused sometimes as it searches for text as I fill in the find box, or switch from Replace to Find, or switch the whole word or wrap icons on and off.
attached is a screen snip, but I can't work out reliably what I do to make it get this wrong: I think I did Replace, followed later on by turning the wrap and whole word icons on, then off, but I hope you can see that SQL Developer's behaviour is wrong. Find box shows 0 or 0, whole word is Off but it fails to find the highlighted text.
As a result I can't trust it and have to search in Notepad++.
SQL Developer Version 18.104.22.168 Build MAIN-20.64
SELECT * FROM v$version;
Oracle Database 11g Enterprise Edition Release 22.214.171.124.0 - 64bit Production
PL/SQL Release 126.96.36.199.0 - Production
"CORE 188.8.131.52.0 Production"
TNS for Linux: Version 184.108.40.206.0 - Production
NLSRTL Version 220.127.116.11.0 - Production
Where or how did it go wrong for you? It's not clear from the description as to what needs addressed.