How to annotated space-seperated tokens?

[fishfree]

I have a plain text file conficious.txt with only one line as below:
孔子 曰 ： 学 而 时 习 之 ， 不 亦 悦 乐 。
I convert it to conficious.folia.xml with txt2folia conficious.txt as below:

<?xml version='1.0' encoding='utf-8'?>
<FoLiA xmlns="http://ilk.uvt.nl/folia" xmlns:xlink="http://www.w3.org/1999/xlink" xml:id="lunyu" version="2.5.3" generator="foliapy-v2.5.12">
  <metadata type="native">
    <annotations>
      <text-annotation set="https://raw.githubusercontent.com/proycon/folia/master/setdefinitions/text.foliaset.ttl">
        <annotator processor="proc.txt2folia.08999826"/>
      </text-annotation>
      <linebreak-annotation>
        <annotator processor="proc.txt2folia.08999826"/>
      </linebreak-annotation>
      <paragraph-annotation>
        <annotator processor="proc.txt2folia.08999826"/>
      </paragraph-annotation>
    </annotations>
    <provenance>
      <processor xml:id="proc.txt2folia.08999826" name="txt2folia" type="auto" version="2.5.8" folia_version="2.5.3" command="txt2folia lunyu.txt" host="DESKTOP-ZWZ" begindatetime="2025-03-20T06:48:42">
        <processor xml:id="proc.txt2folia.08999826.generator" name="foliapy" type="generator" version="2.5.12" folia_version="2.5.3" src="https://github.com/proycon/foliapy"/>
      </processor>
    </provenance>
  </metadata>
  <text xml:id="lunyu.text">
    <p xml:id="lunyu.text.p.1">
      <t>孔子 曰  ：  学 而 时 习 之 ， 不 亦 悦 乐 。<br/></t>
    </p>
  </text>
</FoLiA>

Then upload it into FLAT via the web UI, I cannot select a single tokens or multiple tokens by clicking or dragging to annotate it. Whichever token is clicked, the whole sentence will be selected to annotate:

[proycon]

I replied to this in the earlier issue you opened: proycon/folia#108