Which version of Microsoft.IdentityModel are you using?
Note that to get help, you need to run the latest version.
Im using OpenIddict 3.1.1

Where is the issue?

• [x ] M.IM.JsonWebTokens
• M.IM.KeyVaultExtensions
• M.IM.Logging
• M.IM.ManagedKeyVaultSecurityKey
• M.IM.Protocols
• [x ] M.IM.Protocols.OpenIdConnect
• M.IM.Protocols.SignedHttpRequest
• M.IM.Protocols.WsFederation
• M.IM.TestExtensions
• M.IM.Tokens
• M.IM.Tokens.Saml
• M.IM.Validators
• M.IM.Xml
• S.IM.Tokens.Jwt
• Other (please describe)

Is this a new or an existing app?
The app is in production and I haven't upgraded Microsoft.IdentityModel.*, but started seeing this issue

Repro
Using OpenIddict, see issue here: openiddict/openiddict-core#1426

Expected behavior
The ClaimsIdentity Actor is serialized into the JWT (as an json object with a subset of claims attached to the actor claims identity)

Actual behavior
The ClaimsIdentity Actor is ignored

Possible solution
None