Hi, I have the same issue, please tell me what did you do to fix that.
1. standard V1.03b works fine with e1000 nic.
2. V1.03b with IG88's extra.lzma injected, the network isn't working
My environment is PVE 7.1-7, and I downloaded extra.lzma from this topic
https://xpenology.com/forum/topic/28321-driver-extension-jun-103b104b-for-dsm623-for-918-3615xs-3617xs/