Can't add a new Matter Bridge on iHost

I just rebuilt my entire Zigbee network to use the iHost as my main bridge. However, after repairing all my devices, I noticed that I’m unable to add a new Matter Bridge to the iHost (I previously had Apple HomeKit).
So, I decided to remove all my Bridges to check if it was a bug. I managed to add a new Bridge, now with Alexa, but the option to add another bridge doesn’t appear.
Could this be a bug, the fact that the option doesn’t appear, or is it a limitation of the iHost, allowing only one bridge to be connected at a time?

I’m using the latest version, eWeLink CUBE Version 2.3.4

This is not a bug. It is due to the matter specification. To add ihost matter Bridge to another platform you need to share ihost in the first platform.
In your case you need to share ihost in Alexa for another platform.

How can I do it?
It is best to do it from Apple HomeKit to Alexa or the opposite?

I don’t know what’s better.
I use Hub Matter smartthings.

What platform do you have your hub matter from?

Please check this guide: https://ewelink.cc/how-to-set-up-matter-devices-with-ewelink/