QGIS drag-and-drop forms do not reflect 4-byte characters.

[yamamoto-ryuzo]

When tab names are set in Japanese, all characters seem to be recognized as underscores, as shown below.

</div><ul class="nav nav-tabs">
<li class="active"><a href="#popup_dd_[% $id %]____" `data-toggle="tab">管理者</a></li>
<li class=""><a href="#popup_dd_[% $id %]_____" `data-toggle="tab">路線認定</a></li>
<li class=""><a href="#popup_dd_[% $id %]______" data-toggle="tab">供用開始 `</a></li>
<li class=""><a href="#popup_dd_[% $id %]_______" data-toggle="tab">路線情報 `</a></li>
</ul>

At any rate, it worked when I used a title with a different number of characters.
Method of handling: Enter a space (one-byte character) after the letter so that the number of characters is different.

At first I thought it was a bug in LizmapWebClient, so I sent an issue there, but now it is closed.
3liz/lizmap-web-client#3038