bootstrap popover with form in data-content working in Django 1.11 and 2.0 but not in Django 2.1-3.1

[The Brko]

I have code below and it is working as it should in django 1.11 and after upgrading it works in django 2.0 but for some reason it is not working in higher versions of django starting from 2.1 till 3.1.4. And as I can see it is not pasting correctly here in your preview for my code it is missing closing > for opening button tag

Popover button:

<button 
      type="button" 
      class="btn btn-sm btn-secondary" 
      id="dodaj-poziv-za-clanove-tijela" 
      data-container="body" 
      data-toggle="popover" 
      title="Da li želite da dodate članove tijela u sastanak ?"
      data-content=
      "<form method='POST' action='{% url 'poziv_clanovi_dodaj' poziv_id=poziv.id %}'>
          <button type='submit' class='btn btn-success btn-sm clanovi float-right'>Dodaj</button>
          {% csrf_token %}
        </form>
        "
      > Dodaj poziv za članove tijela</button>

In browser this button looks normal for working django versions 1.11 and 2.0 but in those that are not witch is every version above 2.0 including 2.1,2.2 and 3.0,3.1 it button has "> in it and after submitting i get csrf token error

[Tim Graham]

This ticket tracker isn't for getting help to debug your issue. Please see TicketClosingReasons/UseSupportChannels for ways to get help. If you identify that Django is at fault, please reopen with an explanation.

[The Brko]

Replying to Tim Graham:

This ticket tracker isn't for getting help to debug your issue. Please see TicketClosingReasons/UseSupportChannels for ways to get help. If you identify that Django is at fault, please reopen with an explanation.

If something is working fine in django 2.0 and after upgrading to django 2.2.17 it doesn't and it is a problem of syntax written correctly but not being read well it is fer to conclude that it is django's side of problem.
I will try to ask in other place as you suggested, though no much of expectations to get issue resolved.