Clean downgrade
As far as i remember this Lucee version (5.2.9.31) cannot handle if an installed extension no longer can be loaded (because it is build for a newer Lucee version).
The latest 5.2.9.35 Snapshot should be able to handle this so upgrade to this version.
Or if you prefer to stay on 5.2.9.31 open the file /lucee-server/context/lucee-server.xml search for the following tag and delete it, the restart Lucee
<rhextension file-name="y1xbkpufk7o.lex" id="B737ABC4-D43F-4D91-8E8E973E37C40D1B"
lucee-core-version="5.3.0.35-ALPHA" name="Image extension" release-type="all" start-bundles="false" trial="false" version="1.0.0.24-SNAPSHOT"/>
S3 problem in 5.3
When you downgrade Lucee from 5.3 to 5.2, that has zero influence on your initial issue you had, S3 is not part of Lucee core, it is an extension, sure when you upgrade from 5.2 to 5.3, the S3 extension may also get upgraded in case it not already is, BUT downgrade Lucee again to 5.2 will not touch the S3 extension itself. it will keep S3 on the version it is, Lucee NEVER downgrade extensions.
If you have a problem with the S3 extension, downgrade/upgrade this extension not Lucee.
The issue you saw most likely would be get solved by restarting the servlet engine.
My sugestion, go back to 5.3 and if you have problems with S3, downgrade S3.
I just checked what version are defined as minimal requirement with 5.2 and 5.3, they are the same, so in other words upgrading Lucee from 5.2 to 5.3 did NOT touch S3 at all, a simple restart would solve the issue.