One possible solution would be a Script Trigger (OnModify) that commits the record.
For some reason, if you use a trigger and a commit record script step you need to add a halt script step at the end of the script to make it work properly.
Based on what you said, I think I tried it and it didn't work. (I'm new to Filemaker)
I selected the record "Suburbs" (the popup window) and set a script trigger - OnObjectModify, this opened the specify script. Here I created a script "go to Portal Row"
On the PC, this works fine... Pick a value from the Pop-up menu and then it moves to the first row of the portal. However when copied over to the Ipad - the popup menu remains after being selected.
You'll need to add a step to Commit Record / Request. Also, use Halt Script, as pointed out by rgordon.
Thanks Mike and rgordon for your help and knowledge.
It works.. and I'm very happy.