I looked on the p99 wiki for this but found myself confused when reading this source
https://web.archive.org/web/20020804...html?item=6054
[You must be logged in to view images. Log in or Register.]
and this together
https://web.archive.org/web/20031125...p?Article=4053
Someone wised them up to other classes being able to use the clicky and had to go throw several iterations to get it working the way they wished to. Systems were much jankier back then after all. Nonetheless the fix is beyond the timeline this project adheres to.
Probably best to just chalk this up to not being compatible the servers vision even if it undeniably was an in-era factuality.