postman http get request with authentification fails with 401 reply

Question

I have an IOT device (PV inverter). As with many of these there is an official API mostly for data retrival and some settings. However, given the right credentials (admin account) you can configure significantly more in the webinterface.

I would like to be able to do this from my home automation server directly (via node red finally). So I tried to have a look at the communication between the browser and the inverter via Wireshark. I found some GET an POST calls, and wanted to start with the replication of a GET call via node-red or Postman first.

However, no matter what I tried so far I only get 401 replies. Seemingly, I'm not able to setup the message with proper authentificaion. In wireshark the Postman and the original GET request are very close.

Here is the original (followed by a "200 OK" response):

Internet Protocol Version 4, Src: 192.168.0.64, Dst: 192.168.0.5
Transmission Control Protocol, Src Port: 56183, Dst Port: 80, Seq: 1, Ack: 1, Len: 601
Source Port: 56183
Destination Port: 80
[Stream index: 1]
[Conversation completeness: Incomplete (28)]
[TCP Segment Len: 601]
Sequence Number: 1 (relative sequence number)
Sequence Number (raw): 2463465501
[Next Sequence Number: 602 (relative sequence number)]
Acknowledgment Number: 1 (relative ack number)
Acknowledgment number (raw): 1894190984
0101 .... = Header Length: 20 bytes (5)
Flags: 0x018 (PSH, ACK)
[TCP Flags: ·······AP···]
Window: 512
[Calculated window size: 512]
[Window size scaling factor: -1 (unknown)]
Checksum: 0x8409 [unverified]
[Checksum Status: Unverified]
Urgent Pointer: 0
[Timestamps]
[SEQ/ACK analysis]
TCP payload (601 bytes)
Hypertext Transfer Protocol
GET /commands/StandbyState HTTP/1.1\r\n
Host: 192.168.0.5\r\n
Connection: keep-alive\r\n
Accept: application/json, text/plain, /\r\n
Authorization: Digest username="technician", realm="Webinterface area",
nonce="63af2777:24350f8b8a09fb90b82b6ac480d325cc", uri="/commands/StandbyState", response="a09ac5fe504563040d0ff8acfd68653e", qop=auth, nc=00000022, cnonce="NaN"\r\n

    username="technician"  
    realm="Webinterface area"  
    nonce="63af2777:24350f8b8a09fb90b82b6ac480d325cc"  
    uri="/commands/StandbyState"  
    response="a09ac5fe504563040d0ff8acfd68653e"  
    qop=auth  
    nc=00000022  

User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/108.0.0.0 Safari/537.36\r\n
Referer: http://192.168.0.5/\r\n
Accept-Encoding: gzip, deflate\r\n
Accept-Language: de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7\r\n
\r\n
[Full request URI: http://192.168.0.5/commands/StandbyState]

and here is the captured Postman packet

Internet Protocol Version 4, Src: 192.168.0.64, Dst: 192.168.0.5
Transmission Control Protocol, Src Port: 43404, Dst Port: 80, Seq: 1, Ack: 1, Len: 471
Source Port: 43404
Destination Port: 80
[Stream index: 5]
[Conversation completeness: Incomplete, DATA (15)]
[TCP Segment Len: 471]
Sequence Number: 1 (relative sequence number)
Sequence Number (raw): 990556558
[Next Sequence Number: 472 (relative sequence number)]
Acknowledgment Number: 1 (relative ack number)
Acknowledgment number (raw): 2175082347
0101 .... = Header Length: 20 bytes (5)
Flags: 0x018 (PSH, ACK)
[TCP Flags: ·······AP···]
Window: 513
[Calculated window size: 131328]
[Window size scaling factor: 256]
Checksum: 0x8387 [unverified]
[Checksum Status: Unverified]
Urgent Pointer: 0
[Timestamps]
[SEQ/ACK analysis]
TCP payload (471 bytes)
Hypertext Transfer Protocol
GET /commands/StandbyState HTTP/1.1\r\n
[truncated]Authorization: Digest username="technician", realm="Webinterface area", nonce="63af2777:24350f8b8a09fb90b82b6ac480d325cc", uri="/commands/StandbyState", algorithm="MD5", qop=auth, nc=00000022, cnonce="NaN", response="a09ac5fe5

    username="technician"  
    realm="Webinterface area"  
    nonce="63af2777:24350f8b8a09fb90b82b6ac480d325cc"  
    uri="/commands/StandbyState"  
    algorithm="MD5"  
    qop=auth  
    nc=00000022  
    cnonce="NaN"  

User-Agent: PostmanRuntime/7.30.0\r\n
Accept: /\r\n
Postman-Token: e5d8ee2c-37fb-49ae-aa37-1cf05bfe8608\r\n
Host: 192.168.0.5\r\n
Accept-Encoding: gzip, deflate, br\r\n
Connection: keep-alive\r\n
\r\n
[Full request URI: http://192.168.0.5/commands/StandbyState]
[HTTP request 1/1]

Why does this not work?