flutter - 隐藏密码中星号（*）之间的空格不统一

Question

知道为什么隐藏密码中星星之间的空格不统一吗？它是在做某种分组吗？关于如何使其统一的任何想法？

这是代码片段，

TextField(
          key: const ValueKey('text_field'),
          enableInteractiveSelection: widget.enableInteractiveSelection,
          focusNode: _focusNode,
          obscuringCharacter: widget.obscuringCharacter ?? '•',
          controller: _textEditingController,
          inputFormatters: widget.inputFormatter,
          keyboardType: widget.keyboardType,
          obscureText: widget.obscureText ? _hidePassword : false,
          maxLength: widget.maxLength,
          maxLengthEnforcement:
              MaxLengthEnforcement.truncateAfterCompositionEnds,
          autocorrect: widget.autocorrect,
          enableSuggestions: widget.enableSuggestions,
          textAlignVertical: TextAlignVertical.center,
)