Oct 24 2017
So, I have found where the problem from!
Parameters of the jobs truncated by the type "BLOB" of the row "job_params" of the table "job" but it is 2^16 size limit.
Then I set the row "job_params" to the type "MEDIUMBLOB" and have not more for the problem.
And more, serialize() is not that one which truncate but after it into makeBlob() I have the full sized file.
I hope that also.
Oct 23 2017
I have stable reproduction of the problem which I guess related to somewhere limit in 65536 and if some regular expression is used into unserialize() then it is that one, which I met early and into an other environment.