Hello Antonio,
I managed to fix my phone.
After some research i found forum talking about this issue. Here are the links
[post|563355]
https://discussions.apple.com/thread/250734990?page=1
I went and check the Analytics Data which is provided by the phone when there is an issue.
Settings -> Privacy -> Analytics & Improvements -> Analytics Data
I found many reports intitled “Panic-full“. And after reading the different forums i saw some suggestions telling to change the charging port with an Original or OEM Part. That is were the issue comes from.
So i went to a repair shop and bought a “Used Original iPhone XS charging port”. Went back home and assembled everything and VOILA the different issue were no more.
* No more lags when the cameras are connected
* No more restarting after 3 min.
* Everything works great
* I hope this will be helpfull