I suggest that when inserting a nickname and the cursor is preceded with @, no formatting should be applied.
Step 1. Copy username
Step 2. Type @ in the message editor
Step 3. Press Command-V
Result: @[KhersonGoPri](https://forum.kozovod.com/u/KhersonGoPri)
Suggested improvement would result in: @KhersonGoPri - no formatting applied because the username is being inserted right after the @ sign.
On a laptop, I just select the username and Command-C, so the link with formatting gets copied.