SIP provider OK on an IP phone , but NOK with Jami

Hello

I’va been using a swiss provider (switzernet) since years with my gigaset C450IP

I try since a couple of days to use it with Jami , with the same parameters than the C450IP ..but it fails

Does anybody has an experience with this provider ?

P.S. Jami account is OK (check on my LAN between 2 PC’s)