Can't connect Raspberry Pi Properties to ThingWorx Composer - Error binding properties

• I have a raspberry Pi 3 set up and have my EMS running and the lua script resource running.
• The raspberry pi thing is showing isConnected as true on my Thingworx platform.
• The properties on the raspberry pi are updating every 30 seconds as instructed
• Thingworx Composer is open at localhost:8080/Thingworx/Composer

However, property values are not being pushed to Thingworx. My pi connection was working perfectly up until the middle of April and then wan't used at all until I tried to open my project again today.

Remote bindings are already set up but when I go again to the "manage property bindings tab" I get a message saying "Error browsing properties. Be sure the remote device/server is connected and configured properly".

I now also get the following message in my lua script repeated:

[INFO ] 2018-05-16 14:38:32,799 PiThing: EMS is available: true, online: true
[WARN ] 2018-05-16 14:38:32,799 thingworx.server: Could not set properties on server. code: 500, resp:
[DEBUG] 2018-05-16 14:38:34,305 thingworx.server: Created batch of 6 properties to be pushed to the server (last batch of group).
[DEBUG] 2018-05-16 14:38:34,309 SDK: twTlsClient_Create: Initializing TLS Client
[DEBUG] 2018-05-16 14:38:34,388 TlsStream::doclose: Disconeccting socket
[DEBUG] 2018-05-16 14:38:34,389 SDK: twTlsClient_Close: Disconnecting from server
[DEBUG] 2018-05-16 14:38:34,390 SDK: twTlsClient_Close: Disconnecting from server
[INFO ] 2018-05-16 14:38:34,389 PiThing: Error occured while accessing EMS. Checking isConnected.
[DEBUG] 2018-05-16 14:38:34,390 SDK: twTlsClient_Create: Initializing TLS Client
[DEBUG] 2018-05-16 14:38:34,392 TlsStream::doclose: Disconeccting socket
[DEBUG] 2018-05-16 14:38:34,392 SDK: twTlsClient_Close: Disconnecting from server
[DEBUG] 2018-05-16 14:38:34,393 SDK: twTlsClient_Close: Disconnecting from server
[INFO ] 2018-05-16 14:38:34,394 PiThing: EMS is available: true, online: true

Here is my config.json:

{
 "ws_servers": [{
 "host": "localhost",
 "port": 9000
 }],
 "http_server": {
 "host": "127.0.0.1",
 "port": 8000,
 "ssl": false,
 "authenticate": false
 },
 "appKey": "c9291758-bb3e-45e4-83a8-fb8b8abcff35",
 "logger": {
 "level": "DEBUG"
 },
 "auto_bind": [
 {
 "name": "PiThing",
 "host": "127.0.0.1",
 "port": 8001,
 "protocol": "http",
 "identifier": "KitchenPiThing",
 "gateway": false
 }],
 "certificates": {
 "validate": false,
 "allow_self_signed": true
 },
 "ws_connection": {
 "encryption": "none",
 "verbose": true,
 "msg_timeout": 10000
 }
}

And my config.lua:

scripts.log_level = "DEBUG"
scripts.PiThing = {
 file = "thing.lua",
 template = "PiTemplate",
 identifier = "KitchenPiThing",
 scanRate = 1000,
 taskRate = 30000
 }

scripts.rap_host = "127.0.0.1"
scripts.rap_port = 8000
scripts.rap_ssl = false
scripts.rap_validate = false


scripts.script_resource_host = "127.0.0.1"
scripts.script_resource_port = 8001
scripts.script_resource_ssl = false
scripts.script_resource_authenticate = false

Thanks in advance,

Charlotte