Flask render_template clears all other forms
<p>I have multiple forms with one submit button for each of them, all in one template. <code>render_template</code> returns only empty <code>StringFields</code>. How can I render without touching my other <code>StringFields</code>?</p>

<pre><code>@app.route('/', methods=['GET','POST'])
def index():
    msform = msForm(request.form)
    synform = synForm(request.form)    

    if request.method == 'POST' and msform.validate() and msform.ms_submit.data:
        processed_text = model.most_similar(positive=[msform.ms_3.data, msform.ms_2.data], negative=[msform.ms_1.data])
        msform.ms_submit.label.text = processed_text[0][0]        
        return render_template('my-form.html', msform=msform, synform=synform)        

    elif request.method == 'POST' and synform.validate() and synform.syn_submit:
        processed_text = model.most_similar([synform.syn_1.data])    
        return render_template('my-form.html', msform=msform, synform=synform)

    return render_template('my-form.html', msform=msform, synform=synform)

class msForm(Form):
    ms_1 = StringField(label='Eingabe_1', default = 'king', validators=[validators.DataRequired(message='This Field is required')])
    ms_2 = StringField(label='Eingabe_2', default = 'man', validators=[validators.DataRequired(message='This Field is required')])
    ms_3 = StringField(label='Eingabe_3', default = 'queen', validators=[validators.DataRequired(message='This Field is required')])
    ms_submit = InlineSubmitField(label = '?')

class synForm(Form):
    syn_1 = StringField(label='Eingabe', default = 'king', validators=[validators.DataRequired()])
    syn_submit = InlineSubmitField('?')
</code></pre>