Incomplete String Output...
Hello, did you try to edit the Persistence Level in the flow settings? There should be 2 values, one is Standard and the other is Extended.
I had a similar issue except mine was when I retrieved information from a website.
There shouldn't be any restriction as far as I am familiar, however for your particular situation, could you provide more info - maybe some screenshots. I wonder if you get anything in the logs.
As for the Standard vs Extended - it is explained better here and it worth checking. At runtime full chars should be used even in Standard, however truncation occurs over db persistence.