Both plume and plus versions 8.0.8 of tomee were built without the jsf.js inside the respective jsf libs (jakarta.faces and myfaces). Plus (myfaces) shows up the folloing log:
Plume version silently ignores the problem.
Exchanging the packaged jar with the maven provided ones fixes the issue.
I guess the issue didn't show up in early phases because most of the tests on JSF does not use ajax enabled and that the issue is due some broken filtering (maybe you filtered out *.js or didin't filter them in).
Attached is a slightly modified version of the tomee-webapp with 6 profiles: the default webprofile, plus and plume, the three of them broken when you try to access book.jsf, and 3 others (webprofile-fixed, plus-fixed and plume-fixed), in which I've made the jar substitution. Using mvn -P<profilename> clean package tomee:run will allow checking accessing http://localhost:8080/book.jsf