Hi rocketfoot,
This one has been puzzling me too, but I have a solution
If you look at line 382 of the MyAlerts plugin
myalerts.php file, you'll see that it inserts the code in header_welcomeblock_member and inserts the applicable code after the modcp link.
This works great on the default MyBB theme, but Curves UI puts the User CP / Mod CP / Admin CP in a dropdown menu - and this seems to confuse the plugin.
Open up the header_welcomeblock_member template for Curves UI, find the {$myalerts_headericon} code that was inserted around line 8 and delete it.
Towards the bottom of the file, find this line:
Code:
<li class="list-inline-item ms-2">{$pmslink}</li>
and add this to the line before it
Code:
<li class="list-inline-item ms-2 d-inline-block d-sm-inline-block d-md-inline-block d-lg-none d-xl-none d-xxl-none">{$myalerts_headericon}</li>
Then go and edit the myalerts_headericon template and replace the contents of the file with this
Code:
<li class="alerts {$newAlertsIndicator}" style="display: inline-block;">
<a href="{$mybb->settings['bburl']}/alerts.php" class="myalerts" onclick="MyBB.popupWindow('/alerts.php?modal=1&ret_link={$myalerts_return_link}', { fadeDuration: 250, zIndex: (typeof modal_zindex !== 'undefined' ? modal_zindex : 9999) }); return false;"><i class="fas fa-bell"></i> {$lang->myalerts_alerts}
({$mybb->user['unreadAlerts']})</a>
</li>
This fixes the header icon in Curves UI (as shown below)
There are still other issues, this only fixes the header, and I haven't found fixes for those yet!