Firmware update question

One of our schools was having trouble updating the firmware on their controllers which were stuck on v1.01.
The Brain and all components were happily updated to v1.15 and the controller says “Update Available” but there is no version number in brackets and it won’t let him update to v1.04 on the controller. Latest firmware updater software and it has connected and downloaded the latest firmware for all other components.
We got him round the issue by skipping to v1.16 and v1.05 respectively using the Smart Radio button but was curious as to what was causing the issue with the Modkit/ROBOTC versions - I couldn’t replicate here.