showRecords(relation) and UseSeparateFoundeset behaviour

I don’t know if this is a bug or an expected behaviour but it looks strange to me: I have table Parent and Table Child, there are two relations:
Parent → Child (1-n) (ddt_to_articoli: ddtid = id_ddt)
Child → Parent (1-1) (articoli_to_ddt: id_ddt = ddtid)

I placed a button on a Child form to open the Parent record in his own form (forms.DDT_Scheda):

if (id_ddt)
	{
		forms.DDT_Scheda.controller.showRecords(articoli_to_ddt)
	}
else
	{
		application.beep()
	}

In forms.DDT_Scheda a have a bunch of unrelated tabs based on the same table for the purpose of organizing data nicely and what happen is that forms.DDT_Scheda loads the related record fine but the other tabs continue displaying the previous showed record data.
I thought that if two forms don’t use separate foundset they should always show the same record, is this right?
Or should I have to issue a showRecords(articoli_to_ddt) to all the unrelated tab forms? If so: what is the purpose on UseSperateFoundset?

Any official comments on this post?

No, as soon as you use, showRecords or LoadRecords YOU are setting the foundset. and sharing foundset are broken!

This is expected behaviour.
There can be plenty of disscussions found here on the forum about this issue.

Hope this helps

Thanks!