There are some changes in core template so you should compare with that.
If I see it correctly you change the profile avatar section with this <a href="/users/{{topic.creator.username}}">{{avatar topic.creator imageSize="50"}}</a> is the /users/ path correct? This is going to the user profile instead of open user card. With the default user path it should be /u/.
The other change in your template is if category hidden show the username. Which is clearly visible on your screenshot. I changed that section like this.
Remove this from your template:
{{#if hideCategory}}
<div class='category'>
<span class="author-name"><a href="{{topic.creator.path}}" data-user-card="{{topic.creator.username}}">{{topic.creator.username}}</a></span>
</div>
{{else}}
{{/if}}
And add this to the default {{#unless hideCategory}} with {{else}}.
{{#unless hideCategory}}
{{~raw-plugin-outlet name="topic-list-before-category"}}
<div class='category'>
{{category-link topic.category}}
</div>
{{else}}
<span class="author-name">
<a href="{{topic.creator.path}}" data-user-card="{{topic.creator.username}}">{{topic.creator.username}}</a>
</span>
{{/unless}}
So I suggest to import the whole template and modify it what your needs like this.
<script type='text/x-handlebars' data-template-name='mobile/list/topic-list-item.raw'>
<td class="topic-list-data">
{{~raw-plugin-outlet name="topic-list-before-columns"}}
<div class='pull-left'>
<a href="/users/{{topic.creator.username}}">{{avatar topic.creator imageSize="50"}}</a>
</div>
<div class='right'>
{{~raw-plugin-outlet name="topic-list-before-link"}}
<div class='main-link'>
{{~raw-plugin-outlet name="topic-list-before-status"}}
{{~raw "topic-status" topic=topic~}}
{{~topic-link topic class="raw-link raw-topic-link"}}
{{~#if topic.featured_link~}}
{{~topic-featured-link topic~}}
{{~/if~}}
{{~raw-plugin-outlet name="topic-list-after-title"}}
{{~#if topic.unseen~}}
<span class="topic-post-badges"> <span class="badge-notification new-topic"></span></span>
{{~/if~}}
{{~#if expandPinned~}}
{{~raw "list/topic-excerpt" topic=topic~}}
{{~/if~}}
</div>
<div class='pull-right'>
{{raw "list/post-count-or-badges" topic=topic postBadgesEnabled=showTopicPostBadges}}
</div>
<div class="topic-item-stats clearfix">
{{#unless hideCategory}}
{{~raw-plugin-outlet name="topic-list-before-category"}}
<div class='category'>
{{category-link topic.category}}
</div>
{{else}}
<span class="author-name">
<a href="{{topic.creator.path}}" data-user-card="{{topic.creator.username}}">{{topic.creator.username}}</a>
</span>
{{/unless}}
{{discourse-tags topic mode="list"}}
<div class="pull-right">
<div class='num activity last'>
<span class="age activity" title="{{topic.bumpedAtTitle}}"><a
href="{{topic.lastPostUrl}}">{{format-date topic.bumpedAt format="tiny" noTitle="true"}}</a>
</span>
</div>
</div>
<div class="clearfix"></div>
</div>
</div>
</td>
</script>
This is looking good to me in theme creator. Sorry if I missed something.
Little CSS fix to make the title padding thinner so username can clickable.
.topic-list .main-link a.title {
padding: 0.5em 0;
}

