Testing CLAT for IPv6-only mobile networks

I still have issues with clat. In areas with poor reception or in crowded places where the mobile network is at its limit i barely get the clat interface to show up. Sometimes it doesn’t show up after 30times of disabling and enabling mobile network. Is there a timer which can timeout before the clat interface is established? I am using the 10iii with os 4.5 and my network operator is t-mobile germany.