REST API calls fail with 401 response after previously working

I am trying to run my REST API workflows and after I came back from the break basically zero of my workflows work.

The REST API service I am using authenticates like so:

1. Send a user name and password
2. Receive a token
3. Send the token back to create a session

Once the session is created it works for 30 minutes and all other workflows ran against that same target REST API host would work until it expired.

All of the sudden now nothing works after the session is created. I can send the username/password, receive the token, and create the session (session is created according to my REST target logs) but every call after that fails with a 401 error. It almost seems like the session is not being passed/maintained by vRO for subsequent REST operations. I was using vRO 6.0.3 which was working for two months (all 100+ workflows I have) and then when I returned it wasn't. I build a whole new vRO instance using 7.0 and it fails in the same manner. I have tried multiple REST targets running the same REST version and also tried older and newer  versions and the same thing. As far as I can tell nothing has changed on the target REST host or on the vRO server prior to me trying to fix it by deploying new. I have checked certificates, deleted and re-added the host as a REST host. Any other method I use to access the REST host works (chrome client, various other plugins, powershell) If I try "invoke rest host" command against the host any command that needs a session fails.

Sample failure:

[2016-01-25 15:29:38.307] [I] Request: DynamicWrapper (Instance) : [RESTRequest]-[class com.vmware.o11n.plugin.rest.Request] -- VALUE : com.vmware.o11n.plugin.rest.Request@134e7f3d

[2016-01-25 15:29:38.310] [I] Request URL: https://csg-fa405-1.csgvmw.local/api/1.5/volume

[2016-01-25 15:29:38.375] [I] Response: DynamicWrapper (Instance) : [RESTResponse]-[class com.vmware.o11n.plugin.rest.Response] -- VALUE : com.vmware.o11n.plugin.rest.Response@6e8d9407

[2016-01-25 15:29:38.376] [I] Status code: 401

[2016-01-25 15:29:38.378] [I] Content as string: []

[2016-01-25 15:29:38.379] [I] ****Headers****

[2016-01-25 15:29:38.380] [I] Mon, 25 Jan 2016 23:29:39 GMT

[2016-01-25 15:29:38.381] [I] nginx/1.4.6 (Ubuntu)

[2016-01-25 15:29:38.383] [I] keep-alive

[2016-01-25 15:29:38.384] [I] application/json

[2016-01-25 15:29:38.385] [I] 2

[2016-01-25 15:29:38.399] [E] Error in (Workflow:Invoke a REST operation / Check status code (item3)#1) HTTPError: status code: 401

[2016-01-25 15:29:38.424] [E] Workfow execution stack:

***

item: 'Invoke a REST operation/item3', state: 'failed', business state: 'null', exception: 'HTTPError: status code: 401 (Workflow:Invoke a REST operation / Check status code (item3)#1)'

workflow: 'Invoke a REST operation' (A18080808080808080808080808080808080808001299080088268176866967b3)

|  'attribute': name=errorCode type=string value=

|  'attribute': name=statusCodeAttribute type=number value=401

|  'input': name=restOperation type=REST:RESTOperation value=dunes://service.dunes.ch/CustomSDKObject?id='c475fe68-8751-4543-b7c2-bb2a527a3a8c:45fb1f2c-dac4-4cf3-ae6d-d6378017a956'&dunesName='REST:RESTOperation'

|  'input': name=param_0 type=string value=<>

|  'input': name=param_1 type=string value=<>

|  'input': name=param_2 type=string value=<>

|  'input': name=param_3 type=string value=<>

|  'input': name=param_4 type=string value=<>

|  'input': name=param_5 type=string value=<>

|  'input': name=param_6 type=string value=<>

|  'input': name=param_7 type=string value=<>

|  'input': name=param_8 type=string value=<>

|  'input': name=param_9 type=string value=<>

|  'input': name=param_10 type=string value=<>

|  'input': name=param_11 type=string value=<>

|  'input': name=param_12 type=string value=<>

|  'input': name=param_13 type=string value=<>

|  'input': name=param_14 type=string value=<>

|  'input': name=content type=string value=

|  'input': name=defaultContentType type=string value=

|  'output': name=statusCode type=number value=401

|  'output': name=contentLength type=number value=2

|  'output': name=headers type=Properties value=#[#Server#=#string#nginx/1.4.6 (Ubuntu)#+#Connection#=#string#keep-alive#+#Content-Length#=#string#2#+#Date#=#string#Mon, 25 Jan 2016 23:29:39 GMT#+#Content-Type#=#string#application/json#]#

|  'output': name=contentAsString type=string value=[]

*** End of execution stack.