AJAX request in JSF running in GlassFish 4.1 - jsf

Question

In the JSF Application there is this problem:
The application contains some elements inside a t:dataTable that are f:ajax enabled as following:
<h:form id="form" enctype="multipart/form-data">
<t:dataTable id="someTable" ...>
...
<f:facet name="header">
<t:commandLink action="#{someBean.someAction()}">
<t:outputText value="Some command"/>
<f:ajax execute="#this" render="someTable"/>
</t:commandLink>
</f:facet>
...
</t:dataTable>
</h:form>
The "Some command" should do something and refresh the "someTable" only.
Now the problem is: this scenario is WORKING under GlassFish 3.1.2, but under GlassFish 4.1 it is problematic as following:
The "Some command" works perfectly, and updates the someTable without any problem, but no other non-ajax action elements outside the someTable (or inside the Table) works.
They work, but do not show what they do, so that when we refresh the page, the changes appear.
Now, I tried to make the AJAX as following:
<f:ajax execute="#this" render="form"/>
And everything seems to be working just fine.
I need to update only the table, not the whole form.
Does anyone have a solution (web.xml config) or some tip?
There is no PrimeFaces/ICEFaces/RichFaces used in this project.
Thanks
EDIT: The names are correct (without : as prefixes, or anything else). The exact same scenario works perfectly under GlassFish 3.1.
Do we need to look into some security settings, or other configurations?
EDIT2: as #Tiny said in his comment, without multipart/form-data it worked, but then we can't make any Upload. The Upload doesn't work anymore.