Jwt Security Token HoloLens 2 - unity3d

Question

We are trying to implement an authentication system using JWT Security Tokens on HoloLens 2.
We are using:
Unity 2020.3.28
OpenXR
NuGet Packages:
Microsoft.IdentityModel.JsonWebTokens, v. 6.15.1
Microsoft.IdentityModel.Logging, v. 6.15.1
Microsoft.IdentityModel.Tokens, v. 6.15.1
System.IdentityModel.Tokens.Jwt, v. 6.15.1
Newtonsoft.Json, v. 11.0.2
When receiving the answer from the server we parse it into a JwtSecurityToken using this code snippet:
Debug.Log($"signInResul: {signInResult.IdentityToken}");
var stream = signInResult.IdentityToken;
var handler = new JwtSecurityTokenHandler();
var jsonToken = handler.ReadToken(stream);
Debug.Log($"jsonToken: {jsonToken}");
var tokenS = jsonToken as JwtSecurityToken;
Where the signInResult is the Server answer, and we can also output that the response comes in the correct way.
Now within Unity the parsing happens without any problems, once switching to the HoloLens it doesn't work anymore.
We receive the same answer as within the Unity environment, but the code stops on the line with var handler = new JwtSecurityTokenHandler(); or var jsonToken = handler.ReadToken(stream);, since we never get to Debug.Log($"jsonToken: {jsonToken}");.
Does anybody have experience with Jwt on HoloLens and might know where the issue could lies?
Thanks for the help