I tried recreating this. It looks like the specific character or involvement of iOS are a red herrings. The actual problem from my testing appears to be the inability to copy text within a table in Bear 2 beta Version 2.0 (10936).
I created a new note in Bear 2 beta on macOS with a simple table:
| a | b |
|---|---|
| c | d |
Trying to copy any of the letters fails (selecting any letter and pressing ⌘C or selecting Copy from the context menu) fails – nothing goes into the clipboard. Using any of the Edit > Copy As menu options (plain text, rich text, markdown, HTML) clear the clipboard (maybe puts nil value into the clipboard?).