Change lines

At the moment, you are using user_login where I should have thought display_name would make more sense.

So I suggest changing line 816 of sola-support-tickets/sola-support-tickets.php from
$sola_content .= "<div class='sola_st_post_author_meta'><span class=\"sola_response_user\">".$author_data->user_login."</span><br/><span class=\"sola_response_user_type\">".$author_data->roles[0]."</span><br /><span title=\"".$response_data->post_date."\" class=\"sola_response_time\">".sola_st_time_elapsed_string(strtotime($response_data->post_date))."</span><br />";
to
$sola_content .= "<div class='sola_st_post_author_meta'><span class=\"sola_response_user\">".$author_data->display_name."</span><br/><span class=\"sola_response_user_type\">".$author_data->roles[0]."</span><br /><span title=\"".$response_data->post_date."\" class=\"sola_response_time\">".sola_st_time_elapsed_string(strtotime($response_data->post_date))."</span><br />";

I also suggest changing line 1401 of the same file from
".__("Submitted by ","sola_st")." <span class='sola_st_author_box_name'>".$user_data->user_login."</span><br />
to
".__("Submitted by ","sola_st")." <span class='sola_st_author_box_name'>".$user_data->display_name."</span><br />

https://wordpress.org/plugins/sola-support-tickets/