Something new has started. If I paste a link when composing an email, it’s getting encased in brackets.
Is this a K9 or Gboard update?
“A URI pasted when composing a message will now be surrounded by angle brackets” was part of the change log for K-9 Mail 6.708.
We do this because URL-detection in plain text has a lot of edge cases. Wrapping a URL in angle brackets avoids most of them. This approach also allows you to put punctuation marks after the URL without accidentally breaking it because the punctuation can be interpreted as being part of the URL.