Can you get the flag from the packet capture?
easycap.pcap

Opened the pcap file in Wireshark, noticed that the source IP address 172.31.98.199 was sending data. I applied a filter of that source Ip address and all packets that contained data.

wireshark screenshot

Each packet had an extra byte of data, highlighted above. After combining, these bytes the flag was revealed.

FLAG:385b87afc8671dee07550290d16a8071