DB Version: Oracle 19
OS: Windows 10
SQL Developer: Version 23.1.0.097 Build 097.1607
Auto completion for object names breaks when there are multiple objects with the same initial name pattern.
Steps to replicate:
- Create 2 tables with the same initial strings.

2. Type a select query with the common initial string and press CTRL+SPACEBAR to invoke auto-completion.

3. If you look at the highlighted part in the pop-up, the part in bold is a couple characters behind what I've typed so far.
4. Now, if you select the first table name and press enter, you'll see the issue.

5. The table name populated in the query is wrong.

It prefixed the object name with what I typed so far. This bug isn't in 21.4.3 version.
Note: You might have to run a few unrelated selects to replicate Step 2 (I am able to do that by issuing “select * from dual” a few times).