JPA JSF creating a new record doesn't update the page - jpa

Question

The following p:dialog creates a new comment using:
<p:dialog id="buyDlg" widgetVar="buyDialog" modal="true" resizable="false" appendTo="#(body)"
header="#{myBundle.CreateCommentsTitle}" closeOnEscape="true" width="auto" height="auto">
<h:form id="buyCommentCreateForm">
<h:panelGroup id="buyDisplay">
<p:outputPanel id="buyCommentsPanel">
<p:row>
<p:column>
<p:editor id="commentText" value="#{commentsController.selected.commentText}" style="margin-bottom:10px"/>
</p:column>
</p:row>
</p:outputPanel>
<p:commandButton actionListener="#{commentsController.setBuyComment(pmMainController.selected.idPmMain, commentsController.selected.commentText)}" value="#{myBundle.Save}" update=":PmMainEditForm:display" oncomplete="handleSubmit(xhr,status,args,PF('buyDialog'));">
<p:confirm header="#{myBundle.ConfirmationHeader}" message="#{myBundle.ConfirmEditMessage}" icon="ui-icon-alert"/>
</p:commandButton>
<p:commandButton value="#{myBundle.Cancel}" oncomplete="PF('buyDialog').hide()" update="buyDisplay" process="#this" immediate="true" resetValues="true"/>
</h:panelGroup>
</h:form>
</p:dialog>
Where the save method is:
public void setBuyComment(long idPmMain, String commentText){
PmMain pmMain = pmMainFacadeEJB.find(idPmMain);
Comments comments = new Comments();
pmMain.setBuyComment(comments);
comments.setBuyComment(pmMain);
comments.setCommentText(commentText);
commentsFacadeEJB.edit(comments);
}
Everything works fine but I need to reload the page in order to visualize the comment id in PmMain (it gets inserted above where it says PmMain.setBuyComments(comments)). Any ideas?
EDIT
Adding information about setBuyComment:
For PmMain.setBuyComment I have:
public void setBuyComment(Comments buyComment) {
this.buyComment = buyComment;
}
And for comments.setBuyComment:
public void setBuyComment(PmMain pmMain){
pmMain.setBuyComment(this);
pmMainCollection24.add(pmMain);
}
EDIT 2
The backing Bean from PmMain looks like this:
#Entity
#Table(name = "pm_main")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "PmMain.findAll", query = "SELECT p FROM PmMain p")
, #NamedQuery(name = "PmMain.findByPropId", query = "SELECT p FROM PmMain p WHERE p.propId = :propId")
, #NamedQuery(name = "PmMain.findByPropName", query = "SELECT p FROM PmMain p WHERE p.propName = :propName")
, #NamedQuery(name = "PmMain.findByIdPmMain", query = "SELECT p FROM PmMain p WHERE p.idPmMain = :idPmMain")})
public class PmMain implements Serializable {
private static final long serialVersionUID = 1L;
#Size(max = 25)
#Column(name = "prop_id")
private String propId;
#Size(max = 125)
#Column(name = "prop_name")
private String propName;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id_pm_main")
private Long idPmMain;
#JoinColumn(name = "buy_comment", referencedColumnName = "id_comments")
#ManyToOne
private Comments buyComment;
[... Getters and Setters ...]
And the Comments bean looks like:
#Entity
#Table(name = "comments")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "Comments.findAll", query = "SELECT c FROM Comments c")
, #NamedQuery(name = "Comments.findByCommentText", query = "SELECT c FROM Comments c WHERE c.commentText = :commentText")
, #NamedQuery(name = "Comments.findByIdComments", query = "SELECT c FROM Comments c WHERE c.idComments = :idComments")})
public class Comments implements Serializable {
private static final long serialVersionUID = 1L;
#Size(max = 2147483647)
#Column(name = "comment_text")
private String commentText;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id_comments")
private Long idComments;
#OneToMany(cascade = CascadeType.ALL, mappedBy = "buyComment")
private List<PmMain> pmMainCollection24 = new ArrayList<>();
[... Getters and Setters ...]
public void setBuyComment(PmMain pmMain){
pmMain.setBuyComment(this);
pmMainCollection24.add(pmMain);
}