L2TP/IPSec Client to FritzBox

Hi everyone,

I have a problem with a MikroTik LTE.
I managed to do Site-to-Site vpn between Mikrotik and a FritzBox 7590, I have automatic drops and reconnections, I think due to the fact that the LTE line is not very powerful, but it works.

I was trying to make a backup by putting also an L2TP / IPSec client in the interfaces, I made it with the same data as the IPSec but it always remains on PH2 State in “no phase” and never connects.

I have searched many parts of the forum, they say to do a NAT or open ports, I did that too but the result doesn’t change.

Anyone have any suggestions for me?
Thank you