xDrip follower device receives 401 error and no sensor data from Nightscout

[PABLOMORALESROSA]

Hi, and thank you for your work on Nightscout.
I'm having an issue getting sensor data on a follower device using xDrip.

Setup:
The primary device is an iPhone connected to the sensor via LibreLinkUp.
It uses Shuggah to upload data to Nightscout with the following settings:

• AID follower type = None (just treatments)
• MongoDB URL = <my_database_url>
• API_SECRET =
• From this iPhone, the Nightscout connection test is successful ("Verification succeeded").

Problem:
On an Android phone configured as a Nightscout follower (via xDrip), I get the following issues:

• Error message: 401 unauthorized
• No CGM data or glucose graph is shown
• However, manual entries (e.g. calibrations, insulin, and carbs) do appear normally on all devices
• In fact, even Android devices that show the 401 error and no sensor data are able to send treatment data to the MongoDB and those entries appear correctly in Nightscout.

Troubleshooting steps tried:

• Updated Nightscout to version 15.02
• Recreated the MongoDB database from scratch and reconnected all devices
• Reinstalled xDrip on Android devices (version: 041244d-2020-05-09)
• More unsuccessful approaches

Unfortunately, nothing has solved the issue so far.

Any ideas on what might be causing the 401 error or why xDrip is not showing glucose data would be greatly appreciated. This app ecosystem has been the best for us so far, and we'd love to keep using it.

Thanks in advance for any help!

Screenshot
Screenshot from the Android follower device: no glucose graph displayed, but manual entries (e.g. insulin, carbs, calibrations) are visible

[psonnera]

Use the token style URL http://nightscout.github.io/nightscout/downloaders/#xdrip

[PABLOMORALESROSA]

Thanks.
I've already tried it and the error persists.

[psonnera]

@PABLOMORALESROSA does your API secret contain special characters like /%@: ???

[PABLOMORALESROSA]

Thank you for your interest.
No, my API_SECRET only contains numbers and uppercase and lowercase letters.

[psonnera]

@PABLOMORALESROSA I'm puzzled. Please confirm your URL in Nightscout follow is like https://yourAPISecret@yoursite.domain.fqd or https://yourNightscoutToken@@yoursite.domain.fqd ? Because what xDrip+ says is that the authentication fails.

[PABLOMORALESROSA]

"Yes, I'm confused too. Everything has been checked. Also, I haven't changed either the URL or the API_Secret in the last two years, and everything has always worked fine. In fact, I can upload data to Nightscout without any problems and receive blood glucose data as well as carb and insulin entries. I do have communication with Nightscout, but as shown in the picture, I can't see the graphs or the blood glucose level."

[psonnera]

@PABLOMORALESROSA please confirm you are using a recent xDrip+ version https://github.com/nightscoutfoundation/xdrip/releases

[PABLOMORALESROSA]

Yes, it’s another one of the things I did. I updated the version. Now I have the 041244d-2025.05.09.
I think I’ve done all the checks I could.