Sip registration timeout

Hi,
So I have 2 sip trunks one bramatelecom and the other tektalk from teksavvy.
I registered both trunks successfully and everything works. Now when adding a remote extension I need to activate the ip configuration to dynamic or static and set the internal network autoconfig does that well.

Upon applying setting the teksavvy trunk shows online but in the registered trunks status it doesnt show it registered. So again shows 2 trunks online 1 registered.

I tried so many things but cannot get the sip trunk to register. Sip debug tells me that teksavvy registration timeout and keeps retrying and timesout. Btw the bramatelecom is always perfect.

I can fix this turning the ip settings in sip setings to public ip (even though it is not) but then remote extensions dont work.

My setup: single ip with nat. Tried forwarding 5060 to the box and also tried not doing anything. Either way bramatelecom works and teksavvy doesnt.

I hope someone can help me. And thanks for your time