Two TEXTs unexpected joined together in one RUN

[duanyukai]

I have written a simple tool to generate tables from the json data with parsing text axis and lines data. It works well, but I found some of the texts unexpected joined together.
In Acrobat:

But the pdf2json results in:

"R": [
    {
        "T": "0.9 24 ",
        "S": -1,
        "TS": [
            0,
            15,
            0,
            0
        ]
    }
]

What I expect is that they are two RUNS or TEXTs, each with correct axis.("0.9" and "24")