Lucee 5.3.9 had a change to how it parses cookies which may affect you if you are using CommandBox and SSL. It’s a weird combination, but read this post that describes the issue and how to work around it.
Should be fixed in 18.104.22.168
Give it a go and let us know if it’s fixed
@Gavin_Pickin Can you give this build a go and report back?