The following sequence of commands worked OK for me:

CRTLIB JRNTEST
CRTDTAARA DTAARA(JRNTEST/QDFTJRN) TYPE(*CHAR) LEN(100)
CHGDTAARA DTAARA(JRNTEST/QDFTJRN) VALUE('JRNTEST JRN *FILE *ALLOPR')
CRTJRNRCV JRNRCV(JRNTEST/JRNRCV)
CRTJRN JRN(JRNTEST/JRN) JRNRCV(JRNTEST/JRNRCV)
CRTPF FILE(JRNTEST/TESTFILE) RCDLEN(30)
STRDFU and add a record to JRNTEST/TESTFILE using option 5
DSPJRN JRN(JRNTEST/JRN)

The DSPJRN command showed the following entries:

Sequence Code Type Object Library Job Time
1 J PR QPADEV0001 4:14:40
2 J XP TESTFILE JRNTEST QPADEV0001 4:14:55
3 D CT TESTFILE JRNTEST QPADEV0001 4:14:55
4 D JF TESTFILE JRNTEST QPADEV0001 4:14:55
5 F JM TESTFILE JRNTEST QPADEV0001 4:14:55
6 D MA TESTFILE JRNTEST QPADEV0001 4:14:55
7 F MC TESTFILE JRNTEST QPADEV0001 4:14:55
8 R PT TESTFILE JRNTEST QPADEV0001 4:15:12

with entry 8 showing my new record:

Object . . . . . . . : TESTFILE Library . . . . . . : JRNTEST
Member . . . . . . . : TESTFILE
Incomplete data . . : No Minimized entry data : *NONE
Sequence . . . . . . : 8
Code . . . . . . . . : R - Operation on specific record
Type . . . . . . . . : PT - Record added

Entry specific data
Column *...+....1....+....2....+....3....+....4....+....5
00001 'Make it? '

I did nothing specific to starting the implicit journaling so you may want to double check your actions with the sequence of commands I used above.

I hope this helps,
Bruce Vining