Dspender, I hate to ruin the purity of your thread that has only posts by you.
Between posts #1 and #2, the ARP table in your ISP's router was updated with the "new" (to it) MAC address of the card in your main Astaro. Post #2 implies that you need a multipathing rule to make connections persistant.
Astaro Support should be able to fix this if you can't solve it with a persistance rule. I wish I knew more about this, but I've only played with it a bit.
Cheers - Bob