I might try that tomorrow, Brad, but the fact that the problem goes away when upgrading to 5.3.5.80-SNAPSHOT suggests the problem is with Lucee rather than Tomcat, although I perhaps it could be a combination(?)
It’s more difficult to attribute cause/effect when changes to more than one moving part are involved as you’ll know better than most! Having to keep on top of Lucee, Tomcat and Java, all of which have been pushing significant updates recently, does make maintenance a challenge.