I have an issue with my JLink display on PlatformIO, which I think is a PlatformIO bug as per this thread.
As you also use JLink, can you do me a favour?
Can you create a new blank PIO project for Arduino using the nrf52840DK board, don’t worry that you don’t have that board as the check happens later.
The INI file should be
[env:nrf52840_dk]
platform = nordicnrf52
board = nrf52840_dk
framework = arduino
Then try to debug, I want to see if you get the same output formatting as me before I log it as a bug ticket.