Connection error in "SpeedFusion Bonding"

Hello guys,
I am asking for your help on a problem that I am having, I have configured a pepVPN tunnel between my two devices; My local site is the Balance 30 which receives a WAN Ethernet connection and a cellular connection; The remote site is an UBR LTE ; As I want to have a good bandwidth, my two connections are in priority 1 in the tunnel;
But when I check the tunnel status the cellular link is not connected;
what to do please?