TD3 reward not increasing over time

Hey for a uni project i have implemented td3 and trying to test it on pendulum v1 before using the assigned environment.

Here is the list of my hyperparameters:

            "actor_lr": 0.0001,
            "critic_lr": 0.0001,
            "discount": 0.95,
            "tau": 0.005,
            "batch_size": 128,
            "hidden_dim_critic": [256, 256],
            "hidden_dim_actor": [256, 256],
            "noise": "Gaussian",
            "noise_clip": 0.3,
            "noise_std": 0.2,
            "policy_update_freq": 2,
            "buffer_size": int(1e6),

The issue im facing is that the reward keeps decreasing over time, and saturates at around -1450 after some episodes. Does anyone have any ideas, where my issues could lie?
If needed i could also provide any code where you suspect a bug might be

Reward over time

Thanks in advance for your help!