Navigation Problem - Unread Messages

[Nolrim]

Hello everybody.
Recently our forum has been upgrade, and now we are suffering problems in navigation. When a Member navigates to thread, always go to the end of the page, instead the first unread post.
I've been testing this issue in order to find the problem, but i have no idea. This issue only ocurrs in Windows and Android systems with Firefox and Chrome. IOS devices works fine.
Thanks in advance and sorry for my written english.

Forum URL: https://foroafeitado.com/index.php
I can provide test account.

Forum Specs:
MyBB Version 1.8.20
PHP Version 7.2.16
SQL Engine MySQLi 5.7.25

Forum Plugins:
AutoMedia (4.1.1)
Automention (1.3.5)
DVZ Mentions (1.0.5)
DVZ Secure Content (1.1.5)
Fast Search (4.0)
Google SEO (1.8.3)
Login Password Conversion (1.4.1)
My Advertisements (2.3)
MyAlerts (2.0.3)
Patches (1.5)
PHP and Template Conditionals (2.1)
Quick Advanced Editor Plus (2.1.4)
Recent Threads (17.0)
Skip Validator (1.0)
Tapatalk (4.6.3)
Thank You/Like System (3.2.0)
iAndrew Theme Effects (1.0)
Trader (3.0)
XThreads (1.68)

[Wires]

When members click a thread title from the index page MyBB will send the user to the last page. Have a look on this forum. It's the exact same.

Your forum works fine for me.

[Nolrim]

Thanks for your answer Wires. This part works fine, but always send the user to quick reply, not the first unread message. Even if you click on this link https://foroafeitado.com/thread-compras-...#pid641446 a member should go to post 90 of the thread, however you'll go to quick reply. I only can reproduce this issue as logged user. In previous version this works fine.
I think that the update process was incomplete or erroneous at some point.

[.m.]

^ provide a test user account so that someone can check it

[Nolrim]

U: afeitatest
P: testafeita
This user will be disable in 48 hours.

[Veryard]

Just by have a quick glance when hovering over the link to a thread from the index page you have this parameter at the end ?action=lastpost So I assume this will take them to the last post made on that thread right?

Also whenever you link to a div ID it'll put that at the very top of the page which it is doing, but you have a fixed navigation which makes it seem that it's scrolling further when it isnt.

[Nolrim]

Update: I identify part of the problem but I don't know the reason. Deactivating quick reply option, navigation works fine. 
This is the template we are using:

<div id="quickreply_spinner" class="showthread_spinner" style="display: none"><img src="{$theme['imgdir']}/spinner.gif" /></div>
<br />


{$moderation_notice}
<form method="post" action="newreply.php?tid={$tid}&amp;processed=1" name="quick_reply_form" id="quick_reply_form">
 <input type="hidden" name="my_post_key" value="{$mybb->post_code}" />
 <input type="hidden" name="subject" value="RE: {$reply_subject}" />
 <input type="hidden" name="action" value="do_newreply" />
 <input type="hidden" name="posthash" value="{$posthash}" id="posthash" />
 <input type="hidden" name="quoted_ids" value="" id="quoted_ids" />
 <input type="hidden" name="lastpid" id="lastpid" value="{$last_pid}" />
 <input type="hidden" name="from_page" value="{$page}" />
 <input type="hidden" name="tid" value="{$tid}" />
 <input type="hidden" name="method" value="quickreply" />

 <table border="0" cellspacing="{$theme['borderwidth']}" cellpadding="{$theme['tablespace']}" class="tborder">
 <thead>
 <tr>
 <td class="thead" colspan="2">
 <div class="float_left">
 Respuesta rápida
 </div>
 
 </td>
 </tr>
 </thead>
 <tbody style="{$collapsed['quickreply_e']}" id="quickreply_e">
 <tr>
 
 
 <td class="{$trow}">
 <div style="width: 100%">
 <textarea align="center" style="width: 98%; padding: 4px; margin: 0;" rows="8" cols="80" name="message" id="message" tabindex="1"></textarea>{$codebutquick}
 </div>
 <div class="editor_control_bar" style="width: 99%; padding: 4px; margin-top: 3px; display: none;" id="quickreply_multiquote">
 <span class="smalltext">
 {$lang->quickreply_multiquote_selected} <a href="./newreply.php?tid={$tid}&amp;load_all_quotes=1" onclick="return Thread.loadMultiQuoted();">{$lang->quickreply_multiquote_now}</a> {$lang->or} <a href="javascript:Thread.clearMultiQuoted();">{$lang->quickreply_multiquote_deselect}</a>.
 </span>
 </div>
 <br />
 
 {$option_signature} <label><input type="checkbox" class="checkbox" name="postoptions[disablesmilies]" value="1" /> {$lang->disable_smilies}</label> {$closeoption}
 </td>
 </tr>
 {$captcha}
 <tr>
 <td colspan="2" align="center" class="trow1"><input type="submit" class="button" value="{$lang->post_reply}" tabindex="2" accesskey="s" id="quick_reply_submit" /> <input type="submit" class="button" name="previewpost" value="{$lang->preview_post}" tabindex="3" /></td>
 </tr>
 </tbody>
 </table>
</form>

[Nolrim]

Finally I find it, there's a problem with "Quick Advanced Editor Plus", i deactivated it and i will change for Rin Editor.
Thanks for your help.