The problem is once you use analogWrite on Adafruit nRF52 board, digitalWrites to that pin are ignored.
Arduino had a similar problem digitalWrite and analogWrite do not work in combination · Issue #280 · arduino/ArduinoCore-arc32 · GitHub
and fixed it but Adafruit is so far refusing to fix their problem for over 1 year now.
The issue on Adafruit's github ends with the suggestion to ping if you want this fixed.
My view is that they should either fix the problem or clearly mark the board as not being compatible with the Arduino core functions. Ping them with your thoughts on this at
the Adafruit github issue