I believe this wasn't an issue in previous versions of Fitzroy due to it being passed through as a "character", rather than what now is a coerced "numeric" vector.
I would recommend using the following code to remove the non-numeric characters and preserve the raw jumper number, or not coerce the jumper numbers to numeric class.
Loading in afltables results in Jumper Numbers not appearing correctly.
The players that have an "NA" jumper no. are subs, either subbed on or off during the course of the game.
This can seen by the use of the "up" and "down" arrow used by afltables to denote this status change, example here: https://afltables.com/afl/stats/games/2021/031420210318.html
I believe this wasn't an issue in previous versions of Fitzroy due to it being passed through as a "character", rather than what now is a coerced "numeric" vector.
I would recommend using the following code to remove the non-numeric characters and preserve the raw jumper number, or not coerce the jumper numbers to numeric class.