Here is a previous comment from Matt about this in the linked thread.
https://forums.ootpdevelopments.com/...ks#post4890847
"Short term injuries I believe are 2 weeks or less. Long term injuries are around 6 weeks or more. Anything between those values basically gets "interpolated" between the values. So if you set short as very often and long as never, then a 5 week injury will be very rare, 4 weeks would be average, etc...
They act independent, so no, turning off long term injuries will not increase short term ones."
So, it would seem that there is some kind of issue or these injuries are getting pulled from outside the normal injury system somehow.