This has come from Gentoo's bugzilla: https://bugs.gentoo.org/show_bug.cgi?id=184740
It was logged against joe 3.5 but is also applicable to 3.7.
The line numbers have changed and should now be 781 and 966 instead of 1051 and 1235.
The /etc/joe/jstarrc file has a new setting (line 1235)
which blocks the use of ^P (as set on line 1051) to in a search or
search-and-replace context to find or replace control characters (which are
often a problem in foreign text files). This can be fixed simply by removing
line 1235. The use of ^P to enter control characters has been standard in the
jstar invocation of joe forever. There are plenty of other synonyms for
"uparw,eol", so ^P isn't needed for that.