Support Request: 
### Describe Your Problem

Curtains are not visible among homebridge accessories

### Relevant log output

```shell
Have been using the plugin for a while for Curtains, now they disappeared. Within the plugin the curtains show up, outside of it, however, they are not visible, hence cannot see in homekit either.

One error visible in the logs:

[2021. 12. 07. 22:30:04] [SwitchBot] Failed to Discover Devices. "Request failed with status code 504"

Reinstalled the plugin and did the integration again, did not help. Changed the token, paired again, result is the same.
```


### Config for homebridge-switchbot

```shell
"name": "SwitchBot",
            "credentials": {
                "openToken": "openToken",
                "notice": "Keep your token a secret!"
            },
            "platform": "SwitchBot"
        }
```


### Screenshots

<img width="781" alt="Képernyőfotó 2021-12-07 - 22 37 25" src="https://user-images.githubusercontent.com/75098355/145110128-050e3f03-504a-463b-b61e-95d942af89fe.png">


### Device & Model

SwitchBot Curtain & Hub Mini

### Node.js Version

 v17.2.0

### NPM Version

 1

### Homebridge Version

1.3.8

### Homebridge SwitchBot Plugin Version

1.3.0

### Homebridge Config UI X Plugin Version

4.41.3

### Operating System

Raspbian