react textarea onchange focus change
it is because you are rendering the form in a function inside render().
Every time your state/prop change, the function returns a new form. it caused you to lose focus.
Try putting what's inside the function into your render directly.
<main id="main" role="main">
<div className="container-fluid">
<FormPostSingle />
</div>
</main>
====>
<main id="main" role="main">
<div className="container-fluid">
<form onSubmit={onSubmit}>
<InputText name="title" label="Title" placeholder="Enter a title" onChange={onChange} value={valueTitle} />
<InputSubmit name="Save" />
</form>
</div>
</main>