mysql – MATCH () AGAINST () in Boolean mode: pattern order

Does the order of reasons under against affect something?
Here is a chart that I have:

create the df_test table
(
text t1,
text t2,
FULLTEXT df_test_idx (t1 ASC, t2 ASC)
)

Here are the lines that I have:

t1 | t2
------------------------------------------------
1word2 1sec71 5word5 | word2 1sec8 6word6
word1 sec8 5word5 | word2 sec7 word6
word1 sec8 5word5 | word2 1sec17 word6
word1 sec7 5word5 | word2 1sec8 6word6
word1 sec7 5word5 | word2 sec8 word6
word1 sec7 5word5 | word2 sec7 word6
sometrash9 | sometrash10
sometrash7 | sometrash8
sometrash5 | sometrash6
sometrash3 | sometrash4
sometrash13 | sometrash14
sometrash11 | sometrash12
sometrash1 | sometrash2

The request select * from df_test where match (t1, t2) against (& # 39; 6word * in BOOLEAN MODE) returns 2 rows, which is expected:

t1 | t2
-------------------------------------------
1word2 1sec71 5word5 | word2 1sec8 6word6
word1 sec7 5word5 | word2 1sec8 6word6

The request select * from df_test where match (t1, t2) against (& # 39; "word1 sec8" in BOOLEAN MODE) also returns 2 rows, which is also expected:

t1 | t2
-------------------------------------------
word1 sec8 5word5 | word2 sec7 word6
word1 sec8 5word5 | word2 1sec17 word6

The request select * from df_test where match (t1, t2) against (& # 39; "word1 sec8" 6word * in BOOLEAN MODE) should merge the results, but the same 2 lines as above are returned:

t1 | t2
-------------------------------------------
word1 sec8 5word5 | word2 sec7 word6
word1 sec8 5word5 | word2 1sec17 word6

However, if I change the pattern of patterns, it returns as expected. The request select * from df_test where match (t1, t2) against (& # 39; 6word * "word1 sec8" in BOOLEAN MODE). The result:

t1 | t2
-------------------------------------------
1word2 1sec71 5word5 | word2 1sec8 6word6
word1 sec7 5word5 | word2 1sec8 6word6
word1 sec8 5word5 | word2 sec7 word6
word1 sec8 5word5 | word2 1sec17 word6

Can someone please explain what I miss?