Full-text search does not work if query begins from 0
Are you using MyISAM or InnoDB?

What is the min-word-length?

In InnoDB, with innodb_ft_min_token_size > 2, the +xx leads to finding nothing.  Here's the logic:  + says that it must find the the word xx.  However the token size says that the "word" xx is not indexed.

Note:  I think MyISAM was more lenient.

One workaround:  When building the AGAINST string, don't prepend + to any 'word' shorter than min-token-size.  (I actually have an app that uses this trick; I am happy with the results.)

*06 does not work in FULLTEXT

Under no circumstances can you get FULLTEXT to find pxx by searching for xx.

The 0 is irrelevant.  (If it is relevant, please rephrase the Question with a suitable example.)