Typed or Copied Content Replaces Custom Alert Block Instead of Staying Within It #771

Description:
I have customized a block type "alert" followed by a custom block on the BlockNote homepage.
However, every time I type '-', '*', '+', '1.' or copy a text segment within the same editor, it replaces the "alert" block instead of placing the content within it.

Steps to Reproduce:

1. Create a custom "alert" block as per the documentation.
2. Type '-', '*', '+', '1.' or copy and paste a text segment within the "alert" block.
3. Observe that the content replaces the "alert" block instead of staying within it.

Expected Behavior:
The typed or copied content should remain within the "alert" block instead of replacing it.

Actual Behavior:
The "alert" block is replaced by the typed or copied content.

Link to Documentation:
BlockNote Custom Schemas - Custom Blocks