MacBook Pro (16" 2019) Does Not Recognize Correct Resolution
Confusingly, it does appear to be wire related. I found my original USB-C to USB-C cable which came with the monitor and it resolved the issue.
EDIT (26/03/2021): I spoke too soon. The issue has occured with this cable as well. However, as noted by Luciano, it appears to be a known bug by Apple and will therefore be resolved in a future release.