see:
https://forums.taleworlds.com/index.php?threads/warband-script-enhancer-2-v1-1-4-2.384882/page-121#post-9911258
starting with WSE2 1.140 the text has a faster write instead of slowly drifting, to not run out of buffer space (normally maximum 15 messages are buffered).
This helps keep buffer overflow from happening in large battles; once the message buffer overflows it stops showing text, until reset, and if the modder does not often reset the message buffer then it stays off. I personally reset it by timer every 1.1 hours outside battles and every 30 seconds during a battle, but that's just me.
notice the fix given (to revert back to old text handling):
\Documents\Mount&Blade Warband WSE2\rgl_config.ini
edit to ADD this line:
bFixNotificationMessages=false