CWOP-3 (44.155.254.4) is back up. For future reference if you get occasional data transfer failures when sending to cwop.aprs.net you could send to one of the specific servers. Their IP addresses can be found via a DNS lookup tool. I used
https://www.ultratools.com/tools/dnsLookup and found the IPs below to be in use. A ping of 44.155.254.4 showed it was down so I just sent direct to 66.151.32.203 for the last ~half day. With all servers back up I'm back to sending to cwop.aprs.net. Server status is at this link
http://www.wxqa.com/checkservers3.html.
CWOP-1 thru CWOP-7 not in order:
44.155.254.4
85.188.1.27
129.15.108.116
129.15.108.117
63.251.153.99
137.26.70.99
66.151.32.203