a few things:
- please don’t make the URI case-sensitive: ‘Close’ and ‘close’ should both work
- if -d “{}” isn’t set, then the TCP connection is closed with an empty reply
curl -vv -H "BOND-Token: XYZZY" -i http://ZZFK85187.local/v2/devices/cb233b8eb5300245/actions/Open -X PUT
* Host ZZFK85187.local:80 was resolved.
* IPv6: (none)
* IPv4: 192.168.102.144
* Trying 192.168.102.144:80...
* Connected to ZZFK85187.local (192.168.102.144) port 80
> PUT /v2/devices/cb233b8eb5300245/actions/Open HTTP/1.1
> Host: ZZFK85187.local
> User-Agent: curl/8.7.1
> Accept: */*
> BOND-Token: XYZZY
>* Request completely sent off
* Empty reply from server
* Closing connection
curl: (52) Empty reply from server