### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

Hi, there! I have encountered with a problem that litellm can’t handle a2a “tasks/get” method. I have tried it with default agent and a pydantic one.

### Steps to Reproduce

1. Create basic agent with fasta2a 2. Try to send message via playground 3. See a task with status “submitted” 4. Try to get task status by task_id 5. Get unclear 400 log for 1.81.14 or 500 for 1.83.7 Pydantic ai agents works but only via playground, I also can’t get task by task_id

### Relevant log output

```shell

```

### What part of LiteLLM is this about?

Proxy

### What LiteLLM version are you on ?

v1.81.14 & 1.83.7

### Twitter / LinkedIn details

_No response_