USB WAN not cooperating with the bank website


I have Balance 20 with 3 cellular connections. Two of them are connected through the two WAN ports and one is connected through the USB port. Whenever I have the USB WAN connected, I get an error from my bank. If I put the Mobile Internet Connection(USB) in Backup Priority #2 mode, everything works fine. When I use my USB WAN on the SURF-SOHO it works with no problems. Is there a setting that I’m missing. Also, I noticed on WAN #1 and #2 the Method is showing DHCP and the Mobile Internet connections is showing ‘ppp’ in the method column. Any ideas?